diff --git a/CHANGELOG.md b/CHANGELOG.md
index 250a80c2..431e83e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,16 @@ SPDX-License-Identifier: CC0-1.0
 ## 1.3.7-SNAPSHOT
 - Add `KeyRingUtils.injectCertification(keys, certification)`
 - Bugfix: Fix signature verification when `DecryptionStream` is drained byte-by-byte using `read()` call
+- Refactoring:
+  - Move `ArmorUtils` to `org.pgpainless.ascii_armor` package
+  - Move `ArmoredInputStreamFactory` to `org.pgpainless.ascii_armor` package
+  - Move `ArmoredOutputStreamFactory` to `org.pgpainless.ascii_armor` package
+  - Move `CRCingArmoredInputStreamWrwapper` to `org.pgpainless.ascii_armor` package
+  - Move `SessionKey` to `org.pgpainless.s2k` package
+  - Move `RevocationAttributes` to `org.pgpainless.key` package
+  - Move `UserId` to `org.pgpainless.key` package
+  - Move `Passphrase` to `org.pgpainless.s2k` package
+  - Move `NotationRegistry` to `org.pgpainless.policy` package
 
 ## 1.3.6
 - Remove deprecated methods
diff --git a/pgpainless-cli/src/test/java/org/pgpainless/cli/commands/GenerateCertCmdTest.java b/pgpainless-cli/src/test/java/org/pgpainless/cli/commands/GenerateCertCmdTest.java
index 63afc39f..5b87f12d 100644
--- a/pgpainless-cli/src/test/java/org/pgpainless/cli/commands/GenerateCertCmdTest.java
+++ b/pgpainless-cli/src/test/java/org/pgpainless/cli/commands/GenerateCertCmdTest.java
@@ -28,7 +28,7 @@ import org.pgpainless.cli.TestUtils;
 import org.pgpainless.key.info.KeyInfo;
 import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class GenerateCertCmdTest {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/PGPainless.java b/pgpainless-core/src/main/java/org/pgpainless/PGPainless.java
index 9ff2a3b0..2cc5dfda 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/PGPainless.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/PGPainless.java
@@ -25,7 +25,7 @@ import org.pgpainless.key.modification.secretkeyring.SecretKeyRingEditorInterfac
 import org.pgpainless.key.parsing.KeyRingReader;
 import org.pgpainless.key.util.KeyRingUtils;
 import org.pgpainless.policy.Policy;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 public final class PGPainless {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmorUtils.java
similarity index 99%
rename from pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java
rename to pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmorUtils.java
index 160d8d0a..a8ecf760 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/ArmorUtils.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmorUtils.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.ascii_armor;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -32,6 +32,8 @@ import org.bouncycastle.util.io.Streams;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.decryption_verification.OpenPgpInputStream;
 import org.pgpainless.key.OpenPgpFingerprint;
+import org.pgpainless.util.MultiMap;
+import org.pgpainless.util.Tuple;
 
 public final class ArmorUtils {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/ArmoredInputStreamFactory.java b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmoredInputStreamFactory.java
similarity index 95%
rename from pgpainless-core/src/main/java/org/pgpainless/util/ArmoredInputStreamFactory.java
rename to pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmoredInputStreamFactory.java
index 0c5ceeaf..f843f99a 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/ArmoredInputStreamFactory.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmoredInputStreamFactory.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.ascii_armor;
 
 import java.io.IOException;
 import java.io.InputStream;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/ArmoredOutputStreamFactory.java b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmoredOutputStreamFactory.java
similarity index 98%
rename from pgpainless-core/src/main/java/org/pgpainless/util/ArmoredOutputStreamFactory.java
rename to pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmoredOutputStreamFactory.java
index 2e1377a0..98d268cc 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/ArmoredOutputStreamFactory.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/ArmoredOutputStreamFactory.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.ascii_armor;
 
 import java.io.OutputStream;
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/CRCingArmoredInputStreamWrapper.java b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/CRCingArmoredInputStreamWrapper.java
similarity index 99%
rename from pgpainless-core/src/main/java/org/pgpainless/util/CRCingArmoredInputStreamWrapper.java
rename to pgpainless-core/src/main/java/org/pgpainless/ascii_armor/CRCingArmoredInputStreamWrapper.java
index 2c43339b..78c98723 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/CRCingArmoredInputStreamWrapper.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/CRCingArmoredInputStreamWrapper.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.ascii_armor;
 
 import java.io.IOException;
 import java.io.InputStream;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/package-info.java b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/package-info.java
new file mode 100644
index 00000000..e9eda1cb
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/ascii_armor/package-info.java
@@ -0,0 +1,8 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Classes related to ASCII armoring.
+ */
+package org.pgpainless.ascii_armor;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/ConsumerOptions.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/ConsumerOptions.java
index b6117a60..5c1c6512 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/ConsumerOptions.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/ConsumerOptions.java
@@ -25,9 +25,9 @@ import org.bouncycastle.openpgp.PGPSignature;
 import org.pgpainless.decryption_verification.cleartext_signatures.InMemoryMultiPassStrategy;
 import org.pgpainless.decryption_verification.cleartext_signatures.MultiPassStrategy;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
+import org.pgpainless.s2k.SessionKey;
 import org.pgpainless.signature.SignatureUtils;
-import org.pgpainless.util.Passphrase;
-import org.pgpainless.util.SessionKey;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Options for decryption and signature verification.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/DecryptionStreamFactory.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/DecryptionStreamFactory.java
index 77ad92bb..60e3490c 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/DecryptionStreamFactory.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/DecryptionStreamFactory.java
@@ -60,12 +60,12 @@ import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
+import org.pgpainless.s2k.SessionKey;
 import org.pgpainless.signature.SignatureUtils;
 import org.pgpainless.signature.consumer.DetachedSignatureCheck;
 import org.pgpainless.signature.consumer.OnePassSignatureCheck;
-import org.pgpainless.util.ArmoredInputStreamFactory;
-import org.pgpainless.util.Passphrase;
-import org.pgpainless.util.SessionKey;
+import org.pgpainless.ascii_armor.ArmoredInputStreamFactory;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.Tuple;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/MessageInspector.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/MessageInspector.java
index 3dda0f5d..e47e9768 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/MessageInspector.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/MessageInspector.java
@@ -23,7 +23,7 @@ import org.bouncycastle.openpgp.PGPPBEEncryptedData;
 import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData;
 import org.bouncycastle.openpgp.PGPUtil;
 import org.pgpainless.implementation.ImplementationFactory;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 /**
  * Inspect an OpenPGP message to determine IDs of its encryption keys or whether it is passphrase protected.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java
index 130ea554..8e0cddc2 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java
@@ -25,7 +25,8 @@ import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.exception.SignatureValidationException;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.SubkeyIdentifier;
-import org.pgpainless.util.SessionKey;
+import org.pgpainless.s2k.Passphrase;
+import org.pgpainless.s2k.SessionKey;
 
 public class OpenPgpMetadata {
 
@@ -89,7 +90,7 @@ public class OpenPgpMetadata {
 
     /**
      * Return the {@link SubkeyIdentifier} of the key that was used to decrypt the message.
-     * This can be null if the message was decrypted using a {@link org.pgpainless.util.Passphrase}, or if it was not
+     * This can be null if the message was decrypted using a {@link Passphrase}, or if it was not
      * encrypted at all (e.g. signed only).
      *
      * @return subkey identifier of decryption key
diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/cleartext_signatures/ClearsignedMessageUtil.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/cleartext_signatures/ClearsignedMessageUtil.java
index cd0f6b35..06e16c8c 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/cleartext_signatures/ClearsignedMessageUtil.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/cleartext_signatures/ClearsignedMessageUtil.java
@@ -16,7 +16,7 @@ import org.bouncycastle.openpgp.PGPSignatureList;
 import org.bouncycastle.util.Strings;
 import org.pgpainless.exception.WrongConsumingMethodException;
 import org.pgpainless.implementation.ImplementationFactory;
-import org.pgpainless.util.ArmoredInputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredInputStreamFactory;
 
 /**
  * Utility class to deal with cleartext-signed messages.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionOptions.java b/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionOptions.java
index 6d2ca642..ccc13b25 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionOptions.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionOptions.java
@@ -29,7 +29,7 @@ import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.key.info.KeyAccessor;
 import org.pgpainless.key.info.KeyRingInfo;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Options for the encryption process.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionStream.java b/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionStream.java
index 50f5cb5f..c725e9aa 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionStream.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/EncryptionStream.java
@@ -26,8 +26,8 @@ import org.pgpainless.algorithm.StreamEncoding;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.SubkeyIdentifier;
-import org.pgpainless.util.ArmorUtils;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.ascii_armor.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/ProducerOptions.java b/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/ProducerOptions.java
index a015a581..47e4db1b 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/ProducerOptions.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/encryption_signing/ProducerOptions.java
@@ -12,6 +12,7 @@ import org.bouncycastle.openpgp.PGPLiteralData;
 import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.CompressionAlgorithm;
 import org.pgpainless.algorithm.StreamEncoding;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 
 public final class ProducerOptions {
 
@@ -120,7 +121,7 @@ public final class ProducerOptions {
      * The default value is null, which means no comment header is added.
      * Multiline comments are possible using '\\n'.
      *
-     * Note: If a default header comment is set using {@link org.pgpainless.util.ArmoredOutputStreamFactory#setComment(String)},
+     * Note: If a default header comment is set using {@link ArmoredOutputStreamFactory#setComment(String)},
      * then both comments will be written to the produced ASCII armor.
      *
      * @param comment comment header text
diff --git a/pgpainless-core/src/main/java/org/pgpainless/implementation/BcImplementationFactory.java b/pgpainless-core/src/main/java/org/pgpainless/implementation/BcImplementationFactory.java
index c8e20521..1093d21e 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/implementation/BcImplementationFactory.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/implementation/BcImplementationFactory.java
@@ -48,7 +48,7 @@ import org.bouncycastle.openpgp.operator.jcajce.JcaPGPKeyPair;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class BcImplementationFactory extends ImplementationFactory {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/implementation/ImplementationFactory.java b/pgpainless-core/src/main/java/org/pgpainless/implementation/ImplementationFactory.java
index 94967dee..a5b3e020 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/implementation/ImplementationFactory.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/implementation/ImplementationFactory.java
@@ -31,7 +31,7 @@ import org.bouncycastle.openpgp.operator.SessionKeyDataDecryptorFactory;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public abstract class ImplementationFactory {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/implementation/JceImplementationFactory.java b/pgpainless-core/src/main/java/org/pgpainless/implementation/JceImplementationFactory.java
index 504b197e..195617ed 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/implementation/JceImplementationFactory.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/implementation/JceImplementationFactory.java
@@ -46,7 +46,7 @@ import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.provider.ProviderFactory;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class JceImplementationFactory extends ImplementationFactory {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/util/RevocationAttributes.java b/pgpainless-core/src/main/java/org/pgpainless/key/RevocationAttributes.java
similarity index 99%
rename from pgpainless-core/src/main/java/org/pgpainless/key/util/RevocationAttributes.java
rename to pgpainless-core/src/main/java/org/pgpainless/key/RevocationAttributes.java
index 60a02fea..2b56e468 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/util/RevocationAttributes.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/RevocationAttributes.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.key.util;
+package org.pgpainless.key;
 
 import javax.annotation.Nonnull;
 import java.util.Map;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/util/UserId.java b/pgpainless-core/src/main/java/org/pgpainless/key/UserId.java
similarity index 99%
rename from pgpainless-core/src/main/java/org/pgpainless/key/util/UserId.java
rename to pgpainless-core/src/main/java/org/pgpainless/key/UserId.java
index ca233759..cdcdfc2a 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/util/UserId.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/UserId.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.key.util;
+package org.pgpainless.key;
 
 import javax.annotation.Nonnull;
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java b/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java
index 46aa2baf..2d4afe80 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java
@@ -21,7 +21,7 @@ import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
 import org.pgpainless.implementation.ImplementationFactory;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 /**
  * This class describes a logic of handling a collection of different {@link PGPKeyRing}. The logic was inspired by
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java
index 10970fc2..64b3b7d4 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java
@@ -50,7 +50,7 @@ import org.pgpainless.provider.ProviderFactory;
 import org.pgpainless.signature.subpackets.SelfSignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsHelper;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class KeyRingBuilder implements KeyRingBuilderInterface<KeyRingBuilder> {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilderInterface.java b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilderInterface.java
index ecff123b..bdb69246 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilderInterface.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilderInterface.java
@@ -11,8 +11,8 @@ import javax.annotation.Nonnull;
 
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
-import org.pgpainless.key.util.UserId;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.key.UserId;
+import org.pgpainless.s2k.Passphrase;
 
 public interface KeyRingBuilderInterface<B extends KeyRingBuilderInterface<B>> {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingTemplates.java b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingTemplates.java
index 444e7d74..2b7ceed5 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingTemplates.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingTemplates.java
@@ -16,8 +16,8 @@ import org.pgpainless.key.generation.type.KeyType;
 import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
 import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.generation.type.xdh.XDHSpec;
-import org.pgpainless.key.util.UserId;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.key.UserId;
+import org.pgpainless.s2k.Passphrase;
 
 public final class KeyRingTemplates {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/info/KeyRingInfo.java b/pgpainless-core/src/main/java/org/pgpainless/key/info/KeyRingInfo.java
index b818290b..e577639e 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/info/KeyRingInfo.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/info/KeyRingInfo.java
@@ -41,7 +41,7 @@ import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.exception.KeyException;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.SubkeyIdentifier;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.policy.Policy;
 import org.pgpainless.signature.SignatureUtils;
 import org.pgpainless.signature.consumer.SignaturePicker;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditor.java b/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditor.java
index 20876c36..c42c68ee 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditor.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditor.java
@@ -37,7 +37,7 @@ import org.pgpainless.key.protection.UnprotectedKeysProtector;
 import org.pgpainless.key.protection.fixes.S2KUsageFix;
 import org.pgpainless.key.protection.passphrase_provider.SolitaryPassphraseProvider;
 import org.pgpainless.key.util.KeyRingUtils;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.signature.builder.DirectKeySelfSignatureBuilder;
 import org.pgpainless.signature.builder.PrimaryKeyBindingSignatureBuilder;
 import org.pgpainless.signature.builder.RevocationSignatureBuilder;
@@ -48,7 +48,7 @@ import org.pgpainless.signature.subpackets.SelfSignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsHelper;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsUtil;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.selection.userid.SelectUserId;
 
 import javax.annotation.Nonnull;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditorInterface.java b/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditorInterface.java
index 7014d518..df4bfdcd 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditorInterface.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/modification/secretkeyring/SecretKeyRingEditorInterface.java
@@ -20,10 +20,10 @@ import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.generation.KeySpec;
 import org.pgpainless.key.protection.KeyRingProtectionSettings;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.signature.subpackets.RevocationSignatureSubpackets;
 import org.pgpainless.signature.subpackets.SelfSignatureSubpackets;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.selection.userid.SelectUserId;
 
 public interface SecretKeyRingEditorInterface {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/parsing/KeyRingReader.java b/pgpainless-core/src/main/java/org/pgpainless/key/parsing/KeyRingReader.java
index b5b8ea65..dbfd8a30 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/parsing/KeyRingReader.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/parsing/KeyRingReader.java
@@ -24,7 +24,7 @@ import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
 import org.bouncycastle.util.io.Streams;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.collection.PGPKeyRingCollection;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 public class KeyRingReader {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/BaseSecretKeyRingProtector.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/BaseSecretKeyRingProtector.java
index 5b545c12..1b82063e 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/BaseSecretKeyRingProtector.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/BaseSecretKeyRingProtector.java
@@ -9,7 +9,7 @@ import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
 import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 import javax.annotation.Nullable;
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/CachingSecretKeyRingProtector.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/CachingSecretKeyRingProtector.java
index 8cdb3efb..d81a045e 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/CachingSecretKeyRingProtector.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/CachingSecretKeyRingProtector.java
@@ -17,7 +17,7 @@ import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
 import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Implementation of the {@link SecretKeyRingProtector} which holds a map of key ids and their passwords.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java
index c5745068..3b47b76b 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/PasswordBasedSecretKeyRingProtector.java
@@ -12,7 +12,7 @@ import org.bouncycastle.openpgp.PGPSecretKey;
 import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
 import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Provides {@link PBESecretKeyDecryptor} and {@link PBESecretKeyEncryptor} objects while getting the passphrases
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/SecretKeyRingProtector.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/SecretKeyRingProtector.java
index ee461a4e..7a5f786c 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/SecretKeyRingProtector.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/SecretKeyRingProtector.java
@@ -17,7 +17,7 @@ import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
 import org.bouncycastle.openpgp.operator.PBESecretKeyEncryptor;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
 import org.pgpainless.key.protection.passphrase_provider.SolitaryPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Task of the {@link SecretKeyRingProtector} is to map encryptor/decryptor objects to key-ids.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/UnlockSecretKey.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/UnlockSecretKey.java
index 42a5b9b7..fd613f85 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/UnlockSecretKey.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/UnlockSecretKey.java
@@ -13,7 +13,7 @@ import org.pgpainless.exception.KeyIntegrityException;
 import org.pgpainless.exception.WrongPassphraseException;
 import org.pgpainless.key.info.KeyInfo;
 import org.pgpainless.key.util.PublicKeyParameterValidationUtil;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public final class UnlockSecretKey {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/MapBasedPassphraseProvider.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/MapBasedPassphraseProvider.java
index 859758b1..d63be71e 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/MapBasedPassphraseProvider.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/MapBasedPassphraseProvider.java
@@ -7,7 +7,7 @@ package org.pgpainless.key.protection.passphrase_provider;
 import java.util.Map;
 import javax.annotation.Nullable;
 
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Implementation of the {@link SecretKeyPassphraseProvider} that holds a map of different {@link Passphrase passphrases}.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SecretKeyPassphraseProvider.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SecretKeyPassphraseProvider.java
index 59cb39ce..62dc55fc 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SecretKeyPassphraseProvider.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SecretKeyPassphraseProvider.java
@@ -7,7 +7,7 @@ package org.pgpainless.key.protection.passphrase_provider;
 import javax.annotation.Nullable;
 
 import org.bouncycastle.openpgp.PGPSecretKey;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Interface to allow the user to provide a {@link Passphrase} for an encrypted OpenPGP secret key.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SolitaryPassphraseProvider.java b/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SolitaryPassphraseProvider.java
index b439ef56..ffe5b8ac 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SolitaryPassphraseProvider.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/protection/passphrase_provider/SolitaryPassphraseProvider.java
@@ -6,7 +6,7 @@ package org.pgpainless.key.protection.passphrase_provider;
 
 import javax.annotation.Nullable;
 
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Implementation of the {@link SecretKeyPassphraseProvider} that holds a single {@link Passphrase}.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/NotationRegistry.java b/pgpainless-core/src/main/java/org/pgpainless/policy/NotationRegistry.java
similarity index 97%
rename from pgpainless-core/src/main/java/org/pgpainless/util/NotationRegistry.java
rename to pgpainless-core/src/main/java/org/pgpainless/policy/NotationRegistry.java
index 11aa7651..5ea3caa4 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/NotationRegistry.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/policy/NotationRegistry.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.policy;
 
 import java.util.HashSet;
 import java.util.Set;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/policy/Policy.java b/pgpainless-core/src/main/java/org/pgpainless/policy/Policy.java
index ad9f0635..88a563e0 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/policy/Policy.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/policy/Policy.java
@@ -21,7 +21,6 @@ import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
 import org.pgpainless.util.DateUtil;
-import org.pgpainless.util.NotationRegistry;
 
 /**
  * Policy class used to configure acceptable algorithm suites etc.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java b/pgpainless-core/src/main/java/org/pgpainless/s2k/Passphrase.java
similarity index 99%
rename from pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java
rename to pgpainless-core/src/main/java/org/pgpainless/s2k/Passphrase.java
index 4cef145a..6fcaeb1d 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/Passphrase.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/s2k/Passphrase.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.s2k;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java b/pgpainless-core/src/main/java/org/pgpainless/s2k/SessionKey.java
similarity index 98%
rename from pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java
rename to pgpainless-core/src/main/java/org/pgpainless/s2k/SessionKey.java
index 1e71bb03..8cf650dd 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/util/SessionKey.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/s2k/SessionKey.java
@@ -2,7 +2,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-package org.pgpainless.util;
+package org.pgpainless.s2k;
 
 import javax.annotation.Nonnull;
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/s2k/package-info.java b/pgpainless-core/src/main/java/org/pgpainless/s2k/package-info.java
new file mode 100644
index 00000000..ed7362ee
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/s2k/package-info.java
@@ -0,0 +1,8 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Classes related to symmetric encryption using S2K mechanisms.
+ */
+package org.pgpainless.s2k;
diff --git a/pgpainless-core/src/main/java/org/pgpainless/signature/SignatureUtils.java b/pgpainless-core/src/main/java/org/pgpainless/signature/SignatureUtils.java
index 2b69a832..27a10aff 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/signature/SignatureUtils.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/signature/SignatureUtils.java
@@ -38,9 +38,9 @@ import org.pgpainless.algorithm.negotiation.HashAlgorithmNegotiator;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.util.OpenPgpKeyAttributeUtil;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsUtil;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 /**
  * Utility methods related to signatures.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/signature/consumer/SignatureValidator.java b/pgpainless-core/src/main/java/org/pgpainless/signature/consumer/SignatureValidator.java
index 56614f4f..34b7e5f2 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/signature/consumer/SignatureValidator.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/signature/consumer/SignatureValidator.java
@@ -33,7 +33,7 @@ import org.pgpainless.policy.Policy;
 import org.pgpainless.signature.SignatureUtils;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsUtil;
 import org.pgpainless.util.DateUtil;
-import org.pgpainless.util.NotationRegistry;
+import org.pgpainless.policy.NotationRegistry;
 
 /**
  * A collection of validators that perform validation steps over signatures.
diff --git a/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/RevocationSignatureSubpackets.java b/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/RevocationSignatureSubpackets.java
index 358437dc..f45e5bea 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/RevocationSignatureSubpackets.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/RevocationSignatureSubpackets.java
@@ -8,7 +8,7 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import org.bouncycastle.bcpg.sig.RevocationReason;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 
 public interface RevocationSignatureSubpackets extends BaseSignatureSubpackets {
 
diff --git a/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpackets.java b/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpackets.java
index a2eb1f7d..dd7fac08 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpackets.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpackets.java
@@ -48,7 +48,7 @@ import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.algorithm.SymmetricKeyAlgorithm;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 
 public class SignatureSubpackets
         implements BaseSignatureSubpackets, SelfSignatureSubpackets, CertificationSubpackets, RevocationSignatureSubpackets {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpacketsHelper.java b/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpacketsHelper.java
index 8af60a03..59a67d19 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpacketsHelper.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/signature/subpackets/SignatureSubpacketsHelper.java
@@ -29,7 +29,7 @@ import org.pgpainless.algorithm.Feature;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 
 public class SignatureSubpacketsHelper {
 
diff --git a/pgpainless-core/src/test/java/investigations/InvestigateMultiSEIPMessageHandlingTest.java b/pgpainless-core/src/test/java/investigations/InvestigateMultiSEIPMessageHandlingTest.java
index 3350203a..b3d79f50 100644
--- a/pgpainless-core/src/test/java/investigations/InvestigateMultiSEIPMessageHandlingTest.java
+++ b/pgpainless-core/src/test/java/investigations/InvestigateMultiSEIPMessageHandlingTest.java
@@ -37,7 +37,7 @@ import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * This test is used to investigate, how messages of the form
diff --git a/pgpainless-core/src/test/java/investigations/ModifiedPublicKeysInvestigation.java b/pgpainless-core/src/test/java/investigations/ModifiedPublicKeysInvestigation.java
index ba16e2d0..6eb41594 100644
--- a/pgpainless-core/src/test/java/investigations/ModifiedPublicKeysInvestigation.java
+++ b/pgpainless-core/src/test/java/investigations/ModifiedPublicKeysInvestigation.java
@@ -21,7 +21,7 @@ import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
 import org.pgpainless.key.util.KeyIdUtil;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class ModifiedPublicKeysInvestigation {
 
diff --git a/pgpainless-core/src/test/java/org/bouncycastle/AsciiArmorCRCTests.java b/pgpainless-core/src/test/java/org/bouncycastle/AsciiArmorCRCTests.java
index c3af0bd6..2fd96d6e 100644
--- a/pgpainless-core/src/test/java/org/bouncycastle/AsciiArmorCRCTests.java
+++ b/pgpainless-core/src/test/java/org/bouncycastle/AsciiArmorCRCTests.java
@@ -26,8 +26,8 @@ import org.pgpainless.decryption_verification.DecryptionStream;
 import org.pgpainless.key.OpenPgpV4Fingerprint;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.signature.SignatureUtils;
-import org.pgpainless.util.ArmoredInputStreamFactory;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.ascii_armor.ArmoredInputStreamFactory;
+import org.pgpainless.s2k.Passphrase;
 
 public class AsciiArmorCRCTests {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/CleartextSignatureVerificationTest.java b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/CleartextSignatureVerificationTest.java
index cabfdbb1..f7e3cebb 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/CleartextSignatureVerificationTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/CleartextSignatureVerificationTest.java
@@ -41,7 +41,7 @@ import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.signature.consumer.CertificateValidator;
 import org.pgpainless.signature.SignatureUtils;
 import org.pgpainless.signature.consumer.SignatureVerifier;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 import org.pgpainless.util.TestUtils;
 
 public class CleartextSignatureVerificationTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/MissingPassphraseForDecryptionTest.java b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/MissingPassphraseForDecryptionTest.java
index f7d36aba..a00a4c68 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/MissingPassphraseForDecryptionTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/MissingPassphraseForDecryptionTest.java
@@ -36,7 +36,7 @@ import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class MissingPassphraseForDecryptionTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/ModificationDetectionTests.java b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/ModificationDetectionTests.java
index 2ca265ea..32c6b615 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/ModificationDetectionTests.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/ModificationDetectionTests.java
@@ -25,7 +25,7 @@ import org.pgpainless.exception.MessageNotIntegrityProtectedException;
 import org.pgpainless.exception.ModificationDetectionException;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class ModificationDetectionTests {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/PostponeDecryptionUsingKeyWithMissingPassphraseTest.java b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/PostponeDecryptionUsingKeyWithMissingPassphraseTest.java
index c86a823c..7cb46d1d 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/PostponeDecryptionUsingKeyWithMissingPassphraseTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/PostponeDecryptionUsingKeyWithMissingPassphraseTest.java
@@ -21,7 +21,7 @@ import org.pgpainless.PGPainless;
 import org.pgpainless.key.protection.CachingSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class PostponeDecryptionUsingKeyWithMissingPassphraseTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/WrongSignerUserIdTest.java b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/WrongSignerUserIdTest.java
index b3ecabc8..03a59a9a 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/WrongSignerUserIdTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/decryption_verification/WrongSignerUserIdTest.java
@@ -42,7 +42,7 @@ import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.key.protection.UnlockSecretKey;
 import org.pgpainless.policy.Policy;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class WrongSignerUserIdTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptDecryptTest.java b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptDecryptTest.java
index 88a2c38b..81672263 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptDecryptTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptDecryptTest.java
@@ -46,7 +46,7 @@ import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
 import org.pgpainless.key.util.KeyRingUtils;
 import org.pgpainless.policy.Policy;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import org.pgpainless.util.TestAllImplementations;
 
 public class EncryptDecryptTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionOptionsTest.java b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionOptionsTest.java
index 3e7ccb4d..a02efc41 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionOptionsTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionOptionsTest.java
@@ -35,7 +35,7 @@ import org.pgpainless.key.generation.type.KeyType;
 import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
 import org.pgpainless.key.generation.type.xdh.XDHSpec;
 import org.pgpainless.key.util.KeyRingUtils;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class EncryptionOptionsTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionStreamClosedTest.java b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionStreamClosedTest.java
index 4ac43630..363ad38e 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionStreamClosedTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/EncryptionStreamClosedTest.java
@@ -15,7 +15,7 @@ import org.junit.jupiter.api.TestTemplate;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.pgpainless.PGPainless;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class EncryptionStreamClosedTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/SigningTest.java b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/SigningTest.java
index 156e6b57..e043f764 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/SigningTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/encryption_signing/SigningTest.java
@@ -45,7 +45,7 @@ import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.util.KeyRingUtils;
 import org.pgpainless.util.MultiMap;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.TestAllImplementations;
 
 public class SigningTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/example/Encrypt.java b/pgpainless-core/src/test/java/org/pgpainless/example/Encrypt.java
index ed57b90b..c523cb86 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/example/Encrypt.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/example/Encrypt.java
@@ -27,7 +27,7 @@ import org.pgpainless.encryption_signing.EncryptionStream;
 import org.pgpainless.encryption_signing.ProducerOptions;
 import org.pgpainless.encryption_signing.SigningOptions;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class Encrypt {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/example/GenerateKeys.java b/pgpainless-core/src/test/java/org/pgpainless/example/GenerateKeys.java
index 1e743fa1..ea30ffe1 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/example/GenerateKeys.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/example/GenerateKeys.java
@@ -30,8 +30,8 @@ import org.pgpainless.key.generation.type.ecc.EllipticCurve;
 import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
 import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.info.KeyRingInfo;
-import org.pgpainless.key.util.UserId;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.key.UserId;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * This class demonstrates how to use PGPainless to generate secret keys.
diff --git a/pgpainless-core/src/test/java/org/pgpainless/example/ManagePolicy.java b/pgpainless-core/src/test/java/org/pgpainless/example/ManagePolicy.java
index fa2759dc..8496e775 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/example/ManagePolicy.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/example/ManagePolicy.java
@@ -17,7 +17,7 @@ import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.PublicKeyAlgorithm;
 import org.pgpainless.policy.Policy;
-import org.pgpainless.util.NotationRegistry;
+import org.pgpainless.policy.NotationRegistry;
 
 /**
  * PGPainless comes with an algorithm policy.
diff --git a/pgpainless-core/src/test/java/org/pgpainless/example/ModifyKeys.java b/pgpainless-core/src/test/java/org/pgpainless/example/ModifyKeys.java
index a0785993..734793df 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/example/ModifyKeys.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/example/ModifyKeys.java
@@ -32,7 +32,7 @@ import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
 import org.pgpainless.util.DateUtil;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * PGPainless offers a simple API to modify keys by adding and replacing signatures and/or subkeys.
diff --git a/pgpainless-core/src/test/java/org/pgpainless/example/Sign.java b/pgpainless-core/src/test/java/org/pgpainless/example/Sign.java
index 06228c75..c0118077 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/example/Sign.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/example/Sign.java
@@ -30,7 +30,7 @@ import org.pgpainless.encryption_signing.ProducerOptions;
 import org.pgpainless.encryption_signing.SigningOptions;
 import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 public class Sign {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/example/UnlockSecretKeys.java b/pgpainless-core/src/test/java/org/pgpainless/example/UnlockSecretKeys.java
index c6f227f3..1c24a6b6 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/example/UnlockSecretKeys.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/example/UnlockSecretKeys.java
@@ -16,7 +16,7 @@ import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.CachingSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * {@link PGPSecretKey PGPSecretKeys} are often password protected to prevent unauthorized access.
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/TestKeys.java b/pgpainless-core/src/test/java/org/pgpainless/key/TestKeys.java
index cd4c7319..d85db3d4 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/TestKeys.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/TestKeys.java
@@ -16,7 +16,7 @@ import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
 import org.bouncycastle.openpgp.PGPUtil;
 import org.bouncycastle.openpgp.operator.KeyFingerPrintCalculator;
 import org.bouncycastle.openpgp.operator.bc.BcKeyFingerprintCalculator;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class TestKeys {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/UserIdTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/UserIdTest.java
index 4e596b3f..ea38b929 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/UserIdTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/UserIdTest.java
@@ -5,7 +5,6 @@
 package org.pgpainless.key;
 
 import org.junit.jupiter.api.Test;
-import org.pgpainless.key.util.UserId;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/generation/BrainpoolKeyGenerationTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/generation/BrainpoolKeyGenerationTest.java
index 969a0587..ddeaa113 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/generation/BrainpoolKeyGenerationTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/generation/BrainpoolKeyGenerationTest.java
@@ -28,8 +28,8 @@ import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
 import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.generation.type.xdh.XDHSpec;
 import org.pgpainless.key.info.KeyInfo;
-import org.pgpainless.key.util.UserId;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.key.UserId;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.TestAllImplementations;
 
 public class BrainpoolKeyGenerationTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateEllipticCurveKeyTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateEllipticCurveKeyTest.java
index 8ea4877d..13ccff31 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateEllipticCurveKeyTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateEllipticCurveKeyTest.java
@@ -21,7 +21,7 @@ import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
 import org.pgpainless.key.generation.type.xdh.XDHSpec;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.key.util.UserId;
+import org.pgpainless.key.UserId;
 import org.pgpainless.util.TestAllImplementations;
 
 public class GenerateEllipticCurveKeyTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateKeyWithAdditionalUserIdTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateKeyWithAdditionalUserIdTest.java
index b05dbe1e..3405f3b6 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateKeyWithAdditionalUserIdTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateKeyWithAdditionalUserIdTest.java
@@ -24,7 +24,7 @@ import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.key.generation.type.KeyType;
 import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.util.KeyRingUtils;
-import org.pgpainless.key.util.UserId;
+import org.pgpainless.key.UserId;
 import org.pgpainless.util.DateUtil;
 import org.pgpainless.util.TestAllImplementations;
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateWithEmptyPassphraseTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateWithEmptyPassphraseTest.java
index dbb3f49b..d3d62af8 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateWithEmptyPassphraseTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/generation/GenerateWithEmptyPassphraseTest.java
@@ -17,7 +17,7 @@ import org.pgpainless.algorithm.KeyFlag;
 import org.pgpainless.key.generation.type.KeyType;
 import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Reproduce behavior of https://github.com/pgpainless/pgpainless/issues/16
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/generation/KeyGenerationSubpacketsTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/generation/KeyGenerationSubpacketsTest.java
index 231b0485..b407acc9 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/generation/KeyGenerationSubpacketsTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/generation/KeyGenerationSubpacketsTest.java
@@ -35,7 +35,7 @@ import org.pgpainless.key.generation.type.xdh.XDHSpec;
 import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.signature.subpackets.SelfSignatureSubpackets;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class KeyGenerationSubpacketsTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/info/KeyRingInfoTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/info/KeyRingInfoTest.java
index 61e09477..5701a490 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/info/KeyRingInfoTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/info/KeyRingInfoTest.java
@@ -49,10 +49,10 @@ import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
 import org.pgpainless.key.util.KeyRingUtils;
-import org.pgpainless.key.util.RevocationAttributes;
-import org.pgpainless.key.util.UserId;
+import org.pgpainless.key.RevocationAttributes;
+import org.pgpainless.key.UserId;
 import org.pgpainless.util.DateUtil;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.TestAllImplementations;
 
 public class KeyRingInfoTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/info/UserIdRevocationTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/info/UserIdRevocationTest.java
index fd665901..934c6ea9 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/info/UserIdRevocationTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/info/UserIdRevocationTest.java
@@ -33,7 +33,7 @@ import org.pgpainless.key.generation.type.xdh.XDHSpec;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 
 public class UserIdRevocationTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddSubKeyTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddSubKeyTest.java
index afcf9c98..e6c1d5fd 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddSubKeyTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddSubKeyTest.java
@@ -31,7 +31,7 @@ import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.TestAllImplementations;
 
 public class AddSubKeyTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java
index 19f84930..aa36afbe 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java
@@ -26,9 +26,9 @@ import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
-import org.pgpainless.key.util.UserId;
+import org.pgpainless.key.UserId;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class AddUserIdTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/ChangeSecretKeyRingPassphraseTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/ChangeSecretKeyRingPassphraseTest.java
index a0ea6984..9d1ac39a 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/ChangeSecretKeyRingPassphraseTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/ChangeSecretKeyRingPassphraseTest.java
@@ -33,7 +33,7 @@ import org.pgpainless.key.protection.KeyRingProtectionSettings;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class ChangeSecretKeyRingPassphraseTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/GnuDummyS2KChangePassphraseTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/GnuDummyS2KChangePassphraseTest.java
index 64439775..bfcf08f9 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/GnuDummyS2KChangePassphraseTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/GnuDummyS2KChangePassphraseTest.java
@@ -13,7 +13,7 @@ import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class GnuDummyS2KChangePassphraseTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RefuseToAddWeakSubkeyTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RefuseToAddWeakSubkeyTest.java
index 2570837f..2dbc5acd 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RefuseToAddWeakSubkeyTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RefuseToAddWeakSubkeyTest.java
@@ -26,7 +26,7 @@ import org.pgpainless.key.generation.type.rsa.RsaLength;
 import org.pgpainless.key.modification.secretkeyring.SecretKeyRingEditorInterface;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.policy.Policy;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class RefuseToAddWeakSubkeyTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevocationCertificateTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevocationCertificateTest.java
index ec518847..48f2e660 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevocationCertificateTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevocationCertificateTest.java
@@ -18,7 +18,7 @@ import org.pgpainless.PGPainless;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.util.KeyRingUtils;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 
 public class RevocationCertificateTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeKeyWithGenericCertificationSignatureTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeKeyWithGenericCertificationSignatureTest.java
index b2cd85fc..77a89ce0 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeKeyWithGenericCertificationSignatureTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeKeyWithGenericCertificationSignatureTest.java
@@ -18,7 +18,7 @@ import org.junit.jupiter.api.TestTemplate;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.protection.UnprotectedKeysProtector;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import org.pgpainless.util.TestAllImplementations;
 
 /**
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeSubKeyTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeSubKeyTest.java
index 6a044199..8c5a03be 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeSubKeyTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeSubKeyTest.java
@@ -34,12 +34,12 @@ import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.modification.secretkeyring.SecretKeyRingEditorInterface;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.signature.SignatureUtils;
 import org.pgpainless.signature.subpackets.RevocationSignatureSubpackets;
 import org.pgpainless.signature.subpackets.SignatureSubpacketsUtil;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class RevokeSubKeyTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeUserIdsTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeUserIdsTest.java
index 9dc968ed..d2dc95a6 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeUserIdsTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/RevokeUserIdsTest.java
@@ -19,7 +19,7 @@ import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.info.KeyRingInfo;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.util.selection.userid.SelectUserId;
 
 public class RevokeUserIdsTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingCollectionReaderTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingCollectionReaderTest.java
index 552ae25f..474edc97 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingCollectionReaderTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingCollectionReaderTest.java
@@ -20,7 +20,7 @@ import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.OpenPgpV4Fingerprint;
 import org.pgpainless.key.util.KeyRingUtils;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 
 public class KeyRingCollectionReaderTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingReaderTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingReaderTest.java
index 8a634200..a3261e19 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingReaderTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingReaderTest.java
@@ -40,7 +40,7 @@ import org.pgpainless.key.OpenPgpV4Fingerprint;
 import org.pgpainless.key.collection.PGPKeyRingCollection;
 import org.pgpainless.key.util.KeyRingUtils;
 import org.pgpainless.signature.SignatureUtils;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import org.pgpainless.util.TestUtils;
 
 class KeyRingReaderTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/CachingSecretKeyRingProtectorTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/CachingSecretKeyRingProtectorTest.java
index d1f5f9e6..04b8def9 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/CachingSecretKeyRingProtectorTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/CachingSecretKeyRingProtectorTest.java
@@ -25,7 +25,7 @@ import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class CachingSecretKeyRingProtectorTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/MapBasedPassphraseProviderTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/MapBasedPassphraseProviderTest.java
index 3961a2be..33032d7e 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/MapBasedPassphraseProviderTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/MapBasedPassphraseProviderTest.java
@@ -16,7 +16,7 @@ import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.passphrase_provider.MapBasedPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class MapBasedPassphraseProviderTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseProtectedKeyTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseProtectedKeyTest.java
index 45aaf20f..ac52f816 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseProtectedKeyTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseProtectedKeyTest.java
@@ -19,7 +19,7 @@ import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class PassphraseProtectedKeyTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseTest.java
index 83477b28..2bde8636 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/PassphraseTest.java
@@ -15,7 +15,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class PassphraseTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/SecretKeyRingProtectorTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/SecretKeyRingProtectorTest.java
index a5030f74..f642ed38 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/SecretKeyRingProtectorTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/SecretKeyRingProtectorTest.java
@@ -27,7 +27,7 @@ import org.junit.jupiter.api.extension.ExtendWith;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.passphrase_provider.SecretKeyPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import org.pgpainless.util.TestAllImplementations;
 
 public class SecretKeyRingProtectorTest {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/UnlockSecretKeyTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/UnlockSecretKeyTest.java
index c6a35ea9..f30e73a6 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/UnlockSecretKeyTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/UnlockSecretKeyTest.java
@@ -17,7 +17,7 @@ import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.exception.WrongPassphraseException;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class UnlockSecretKeyTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/protection/fixes/S2KUsageFixTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/protection/fixes/S2KUsageFixTest.java
index f324892f..eaf80418 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/protection/fixes/S2KUsageFixTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/protection/fixes/S2KUsageFixTest.java
@@ -24,7 +24,7 @@ import org.pgpainless.PGPainless;
 import org.pgpainless.decryption_verification.ConsumerOptions;
 import org.pgpainless.decryption_verification.DecryptionStream;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class S2KUsageFixTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/util/RevocationAttributesTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/util/RevocationAttributesTest.java
index 8f588a28..bf2a816c 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/util/RevocationAttributesTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/util/RevocationAttributesTest.java
@@ -5,6 +5,7 @@
 package org.pgpainless.key.util;
 
 import org.junit.jupiter.api.Test;
+import org.pgpainless.key.RevocationAttributes;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
diff --git a/pgpainless-core/src/test/java/org/pgpainless/signature/subpackets/SignatureSubpacketsTest.java b/pgpainless-core/src/test/java/org/pgpainless/signature/subpackets/SignatureSubpacketsTest.java
index 988bc776..ece91941 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/signature/subpackets/SignatureSubpacketsTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/signature/subpackets/SignatureSubpacketsTest.java
@@ -53,9 +53,9 @@ import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.key.util.RevocationAttributes;
+import org.pgpainless.key.RevocationAttributes;
 import org.pgpainless.util.DateUtil;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class SignatureSubpacketsTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/MultiPassphraseSymmetricEncryptionTest.java b/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/MultiPassphraseSymmetricEncryptionTest.java
index 5132ef57..073b1cdd 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/MultiPassphraseSymmetricEncryptionTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/MultiPassphraseSymmetricEncryptionTest.java
@@ -20,7 +20,7 @@ import org.pgpainless.encryption_signing.EncryptionOptions;
 import org.pgpainless.encryption_signing.EncryptionStream;
 import org.pgpainless.encryption_signing.ProducerOptions;
 import org.pgpainless.util.TestAllImplementations;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class MultiPassphraseSymmetricEncryptionTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/SymmetricEncryptionTest.java b/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/SymmetricEncryptionTest.java
index d3c503ab..43bb169e 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/SymmetricEncryptionTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/symmetric_encryption/SymmetricEncryptionTest.java
@@ -33,7 +33,7 @@ import org.pgpainless.key.protection.KeyRingProtectionSettings;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.passphrase_provider.SolitaryPassphraseProvider;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 /**
  * Test parallel symmetric and public key encryption/decryption.
diff --git a/pgpainless-core/src/test/java/org/pgpainless/util/ArmorUtilsTest.java b/pgpainless-core/src/test/java/org/pgpainless/util/ArmorUtilsTest.java
index c320c649..ec9abdea 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/util/ArmorUtilsTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/util/ArmorUtilsTest.java
@@ -34,11 +34,15 @@ import org.junit.jupiter.api.extension.ExtendWith;
 import org.pgpainless.PGPainless;
 import org.pgpainless.algorithm.HashAlgorithm;
 import org.pgpainless.algorithm.KeyFlag;
+import org.pgpainless.ascii_armor.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmoredInputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import org.pgpainless.implementation.ImplementationFactory;
 import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.generation.KeySpec;
 import org.pgpainless.key.generation.type.ecc.EllipticCurve;
 import org.pgpainless.key.generation.type.ecc.ecdsa.ECDSA;
+import org.pgpainless.s2k.Passphrase;
 
 public class ArmorUtilsTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/util/ArmoredInputStreamFactoryTest.java b/pgpainless-core/src/test/java/org/pgpainless/util/ArmoredInputStreamFactoryTest.java
index 147b957d..e7f8ae23 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/util/ArmoredInputStreamFactoryTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/util/ArmoredInputStreamFactoryTest.java
@@ -6,6 +6,8 @@ package org.pgpainless.util;
 
 import org.bouncycastle.bcpg.ArmoredInputStream;
 import org.junit.jupiter.api.Test;
+import org.pgpainless.ascii_armor.ArmoredInputStreamFactory;
+import org.pgpainless.ascii_armor.CRCingArmoredInputStreamWrapper;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
diff --git a/pgpainless-core/src/test/java/org/pgpainless/util/NotationRegistryTest.java b/pgpainless-core/src/test/java/org/pgpainless/util/NotationRegistryTest.java
index 3568e143..68a44495 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/util/NotationRegistryTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/util/NotationRegistryTest.java
@@ -9,6 +9,7 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import org.junit.jupiter.api.Test;
+import org.pgpainless.policy.NotationRegistry;
 
 public class NotationRegistryTest {
 
diff --git a/pgpainless-core/src/test/java/org/pgpainless/util/selection/userid/SelectUserIdTest.java b/pgpainless-core/src/test/java/org/pgpainless/util/selection/userid/SelectUserIdTest.java
index 3a49247c..0a57191d 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/util/selection/userid/SelectUserIdTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/util/selection/userid/SelectUserIdTest.java
@@ -9,7 +9,7 @@ import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.key.util.UserId;
+import org.pgpainless.key.UserId;
 
 import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/ArmorImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/ArmorImpl.java
index 71bc3e6b..9f3b094e 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/ArmorImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/ArmorImpl.java
@@ -11,7 +11,7 @@ import java.io.OutputStream;
 
 import org.bouncycastle.bcpg.ArmoredOutputStream;
 import org.bouncycastle.util.io.Streams;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import sop.Ready;
 import sop.enums.ArmorLabel;
 import sop.exception.SOPGPException;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/DecryptImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/DecryptImpl.java
index 4957f748..380524de 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/DecryptImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/DecryptImpl.java
@@ -25,7 +25,7 @@ import org.pgpainless.decryption_verification.OpenPgpMetadata;
 import org.pgpainless.decryption_verification.SignatureVerification;
 import org.pgpainless.exception.MissingDecryptionMethodException;
 import org.pgpainless.exception.WrongPassphraseException;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import sop.DecryptionResult;
 import sop.ReadyWithResult;
 import sop.SessionKey;
@@ -70,7 +70,7 @@ public class DecryptImpl implements Decrypt {
     @Override
     public DecryptImpl withSessionKey(SessionKey sessionKey) throws SOPGPException.UnsupportedOption {
         consumerOptions.setSessionKey(
-                new org.pgpainless.util.SessionKey(
+                new org.pgpainless.s2k.SessionKey(
                         SymmetricKeyAlgorithm.requireFromId(sessionKey.getAlgorithm()),
                         sessionKey.getKey()));
         return this;
@@ -160,7 +160,7 @@ public class DecryptImpl implements Decrypt {
 
                 SessionKey sessionKey = null;
                 if (metadata.getSessionKey() != null) {
-                    org.pgpainless.util.SessionKey sk = metadata.getSessionKey();
+                    org.pgpainless.s2k.SessionKey sk = metadata.getSessionKey();
                     sessionKey = new SessionKey(
                             (byte) sk.getAlgorithm().getAlgorithmId(),
                             sk.getKey()
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/DetachedSignImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/DetachedSignImpl.java
index 0ce326a9..9fe1ad86 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/DetachedSignImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/DetachedSignImpl.java
@@ -26,8 +26,8 @@ import org.pgpainless.encryption_signing.SigningOptions;
 import org.pgpainless.exception.KeyException;
 import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.key.info.KeyRingInfo;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
+import org.pgpainless.s2k.Passphrase;
 import sop.MicAlg;
 import sop.ReadyWithResult;
 import sop.SigningResult;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/EncryptImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/EncryptImpl.java
index 1b95d87c..51acc272 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/EncryptImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/EncryptImpl.java
@@ -27,7 +27,7 @@ import org.pgpainless.exception.KeyException;
 import org.pgpainless.exception.WrongPassphraseException;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.info.KeyRingInfo;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import sop.Ready;
 import sop.enums.EncryptAs;
 import sop.exception.SOPGPException;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/ExtractCertImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/ExtractCertImpl.java
index 5f694208..6ffed803 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/ExtractCertImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/ExtractCertImpl.java
@@ -15,7 +15,7 @@ import org.bouncycastle.openpgp.PGPPublicKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
 import org.pgpainless.PGPainless;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 import sop.Ready;
 import sop.exception.SOPGPException;
 import sop.operation.ExtractCert;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/GenerateKeyImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/GenerateKeyImpl.java
index 893c8dd8..1c12b11e 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/GenerateKeyImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/GenerateKeyImpl.java
@@ -18,8 +18,8 @@ import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.pgpainless.PGPainless;
 import org.pgpainless.key.modification.secretkeyring.SecretKeyRingEditorInterface;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
-import org.pgpainless.util.ArmorUtils;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.ascii_armor.ArmorUtils;
+import org.pgpainless.s2k.Passphrase;
 import sop.Ready;
 import sop.exception.SOPGPException;
 import sop.operation.GenerateKey;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineDetachImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineDetachImpl.java
index 178018aa..d9e583e3 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineDetachImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineDetachImpl.java
@@ -24,7 +24,7 @@ import org.pgpainless.decryption_verification.OpenPgpInputStream;
 import org.pgpainless.decryption_verification.cleartext_signatures.ClearsignedMessageUtil;
 import org.pgpainless.exception.WrongConsumingMethodException;
 import org.pgpainless.implementation.ImplementationFactory;
-import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.ascii_armor.ArmoredOutputStreamFactory;
 import sop.ReadyWithResult;
 import sop.Signatures;
 import sop.exception.SOPGPException;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineSignImpl.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineSignImpl.java
index 3bdc8fc3..c0553eed 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineSignImpl.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/InlineSignImpl.java
@@ -23,7 +23,7 @@ import org.pgpainless.encryption_signing.SigningOptions;
 import org.pgpainless.exception.KeyException;
 import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.info.KeyRingInfo;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 import sop.Ready;
 import sop.enums.InlineSignAs;
 import sop.exception.SOPGPException;
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/MatchMakingSecretKeyRingProtector.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/MatchMakingSecretKeyRingProtector.java
index df54583e..fead8c43 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/MatchMakingSecretKeyRingProtector.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/MatchMakingSecretKeyRingProtector.java
@@ -18,7 +18,7 @@ import org.pgpainless.key.info.KeyInfo;
 import org.pgpainless.key.protection.CachingSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
 import org.pgpainless.key.protection.UnlockSecretKey;
-import org.pgpainless.util.Passphrase;
+import org.pgpainless.s2k.Passphrase;
 
 public class MatchMakingSecretKeyRingProtector implements SecretKeyRingProtector {
 
diff --git a/pgpainless-sop/src/test/java/org/pgpainless/sop/ArmorTest.java b/pgpainless-sop/src/test/java/org/pgpainless/sop/ArmorTest.java
index 95129dfa..a5458898 100644
--- a/pgpainless-sop/src/test/java/org/pgpainless/sop/ArmorTest.java
+++ b/pgpainless-sop/src/test/java/org/pgpainless/sop/ArmorTest.java
@@ -15,7 +15,7 @@ import java.security.NoSuchAlgorithmException;
 import org.bouncycastle.openpgp.PGPException;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 import sop.enums.ArmorLabel;
 import sop.exception.SOPGPException;
 
diff --git a/pgpainless-sop/src/test/java/org/pgpainless/sop/IncapableKeysTest.java b/pgpainless-sop/src/test/java/org/pgpainless/sop/IncapableKeysTest.java
index 5139bbf6..6c1d302d 100644
--- a/pgpainless-sop/src/test/java/org/pgpainless/sop/IncapableKeysTest.java
+++ b/pgpainless-sop/src/test/java/org/pgpainless/sop/IncapableKeysTest.java
@@ -14,7 +14,7 @@ import org.pgpainless.key.generation.KeySpec;
 import org.pgpainless.key.generation.type.KeyType;
 import org.pgpainless.key.generation.type.ecc.EllipticCurve;
 import org.pgpainless.key.generation.type.eddsa.EdDSACurve;
-import org.pgpainless.util.ArmorUtils;
+import org.pgpainless.ascii_armor.ArmorUtils;
 import sop.SOP;
 import sop.exception.SOPGPException;