diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/KeyFlag.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/KeyFlag.java
deleted file mode 100644
index 149ef9d0..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/KeyFlag.java
+++ /dev/null
@@ -1,121 +0,0 @@
-// SPDX-FileCopyrightText: 2018 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.algorithm;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.bouncycastle.bcpg.sig.KeyFlags;
-
-/**
- * Enumeration of different key flags.
- * Key flags denote different capabilities of a key pair.
- *
- * @see <a href="https://tools.ietf.org/html/rfc4880#section-5.2.3.21">RFC4880: Key Flags</a>
- */
-public enum KeyFlag {
-
-    /**
-     * This key may be used to certify third-party keys.
-     */
-    CERTIFY_OTHER  (KeyFlags.CERTIFY_OTHER),
-
-    /**
-     * This key may be used to sign data.
-     */
-    SIGN_DATA      (KeyFlags.SIGN_DATA),
-
-    /**
-     * This key may be used to encrypt communications.
-     */
-    ENCRYPT_COMMS  (KeyFlags.ENCRYPT_COMMS),
-
-    /**
-     * This key may be used to encrypt storage.
-     */
-    ENCRYPT_STORAGE(KeyFlags.ENCRYPT_STORAGE),
-
-    /**
-     * The private component of this key may have been split by a secret-sharing mechanism.
-     */
-    SPLIT          (KeyFlags.SPLIT),
-
-    /**
-     * This key may be used for authentication.
-     */
-    AUTHENTICATION (KeyFlags.AUTHENTICATION),
-
-    /**
-     * The private component of this key may be in the possession of more than one person.
-     */
-    SHARED         (KeyFlags.SHARED),
-    ;
-
-    private final int flag;
-
-    KeyFlag(int flag) {
-        this.flag = flag;
-    }
-
-    /**
-     * Return the numeric id of the {@link KeyFlag}.
-     *
-     * @return numeric id
-     */
-    public int getFlag() {
-        return flag;
-    }
-
-    /**
-     * Convert a bitmask into a list of {@link KeyFlag KeyFlags}.
-     *
-     * @param bitmask bitmask
-     * @return list of key flags encoded by the bitmask
-     */
-    public static List<KeyFlag> fromBitmask(int bitmask) {
-        List<KeyFlag> flags = new ArrayList<>();
-        for (KeyFlag f : KeyFlag.values()) {
-            if ((bitmask & f.flag) != 0) {
-                flags.add(f);
-            }
-        }
-        return flags;
-    }
-
-    /**
-     * Encode a list of {@link KeyFlag KeyFlags} into a bitmask.
-     *
-     * @param flags list of flags
-     * @return bitmask
-     */
-    public static int toBitmask(KeyFlag... flags) {
-        int mask = 0;
-        for (KeyFlag f : flags) {
-            mask |= f.getFlag();
-        }
-        return mask;
-    }
-
-    /**
-     * Return true if the provided bitmask has the bit for the provided flag set.
-     * Return false if the mask does not contain the flag.
-     *
-     * @param mask bitmask
-     * @param flag flag to be tested for
-     * @return true if flag is set, false otherwise
-     */
-    public static boolean hasKeyFlag(int mask, KeyFlag flag) {
-        return (mask & flag.getFlag()) == flag.getFlag();
-    }
-
-    public static boolean containsAny(int mask, KeyFlag... flags) {
-        for (KeyFlag flag : flags) {
-            if (hasKeyFlag(mask, flag)) {
-                return true;
-            }
-        }
-        return false;
-    }
-}
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/KeyFlag.kt b/pgpainless-core/src/main/java/org/pgpainless/algorithm/KeyFlag.kt
new file mode 100644
index 00000000..d8686cd6
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/KeyFlag.kt
@@ -0,0 +1,92 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm
+
+enum class KeyFlag(val flag: Int) {
+
+    /**
+     * This key may be used to certify third-party keys.
+     */
+    CERTIFY_OTHER  (1),
+
+    /**
+     * This key may be used to sign data.
+     */
+    SIGN_DATA      (2),
+
+    /**
+     * This key may be used to encrypt communications.
+     */
+    ENCRYPT_COMMS  (4),
+
+    /**
+     * This key may be used to encrypt storage.
+     */
+    ENCRYPT_STORAGE(8),
+
+    /**
+     * The private component of this key may have been split by a secret-sharing mechanism.
+     */
+    SPLIT          (16),
+
+    /**
+     * This key may be used for authentication.
+     */
+    AUTHENTICATION (32),
+
+    /**
+     * The private component of this key may be in the possession of more than one person.
+     */
+    SHARED         (128),
+    ;
+
+    companion object {
+
+        /**
+         * Convert a bitmask into a list of [KeyFlags][KeyFlag].
+         *
+         * @param bitmask bitmask
+         * @return list of key flags encoded by the bitmask
+         */
+        @JvmStatic
+        fun fromBitmask(bitmask: Int): List<KeyFlag> {
+            return values().filter {
+                it.flag and bitmask != 0
+            }
+        }
+
+        /**
+         * Encode a list of {@link KeyFlag KeyFlags} into a bitmask.
+         *
+         * @param flags list of flags
+         * @return bitmask
+         */
+        @JvmStatic
+        fun toBitmask(vararg flags: KeyFlag): Int {
+            return flags.map { it.flag }.reduceOrNull { mask, f -> mask or f }
+                    ?: 0
+        }
+
+        /**
+         * Return true if the provided bitmask has the bit for the provided flag set.
+         * Return false if the mask does not contain the flag.
+         *
+         * @param mask bitmask
+         * @param flag flag to be tested for
+         * @return true if flag is set, false otherwise
+         */
+        @JvmStatic
+        fun hasKeyFlag(mask: Int, flag: KeyFlag): Boolean {
+            return mask and flag.flag == flag.flag
+        }
+
+        @JvmStatic
+        fun containsAny(mask: Int, vararg flags: KeyFlag): Boolean {
+            return flags.any {
+                hasKeyFlag(mask, it)
+            }
+        }
+    }
+}
\ No newline at end of file