diff --git a/sop-java/src/main/java/sop/operation/RevokeKey.java b/sop-java/src/main/java/sop/operation/RevokeKey.java
deleted file mode 100644
index 3ceb5b3..0000000
--- a/sop-java/src/main/java/sop/operation/RevokeKey.java
+++ /dev/null
@@ -1,54 +0,0 @@
-// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop.operation;
-
-import sop.Ready;
-import sop.exception.SOPGPException;
-import sop.util.UTF8Util;
-
-import java.io.ByteArrayInputStream;
-import java.io.InputStream;
-
-public interface RevokeKey {
-
-    /**
-     * Disable ASCII armor encoding.
-     *
-     * @return builder instance
-     */
-    RevokeKey noArmor();
-
-    /**
-     * Provide the decryption password for the secret key.
-     *
-     * @param password password
-     * @return builder instance
-     * @throws SOPGPException.UnsupportedOption if the implementation does not support key passwords
-     * @throws SOPGPException.PasswordNotHumanReadable if the password is not human-readable
-     */
-    default RevokeKey withKeyPassword(String password)
-            throws SOPGPException.UnsupportedOption,
-            SOPGPException.PasswordNotHumanReadable {
-        return withKeyPassword(password.getBytes(UTF8Util.UTF8));
-    }
-
-    /**
-     * Provide the decryption password for the secret key.
-     *
-     * @param password password
-     * @return builder instance
-     * @throws SOPGPException.UnsupportedOption if the implementation does not support key passwords
-     * @throws SOPGPException.PasswordNotHumanReadable if the password is not human-readable
-     */
-    RevokeKey withKeyPassword(byte[] password)
-            throws SOPGPException.UnsupportedOption,
-            SOPGPException.PasswordNotHumanReadable;
-
-    default Ready keys(byte[] bytes) {
-        return keys(new ByteArrayInputStream(bytes));
-    }
-
-    Ready keys(InputStream keys);
-}
diff --git a/sop-java/src/main/kotlin/sop/operation/RevokeKey.kt b/sop-java/src/main/kotlin/sop/operation/RevokeKey.kt
new file mode 100644
index 0000000..f3cbe5c
--- /dev/null
+++ b/sop-java/src/main/kotlin/sop/operation/RevokeKey.kt
@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.operation
+
+import java.io.InputStream
+import sop.Ready
+import sop.exception.SOPGPException.PasswordNotHumanReadable
+import sop.exception.SOPGPException.UnsupportedOption
+import sop.util.UTF8Util
+
+interface RevokeKey {
+
+    /**
+     * Disable ASCII armor encoding.
+     *
+     * @return builder instance
+     */
+    fun noArmor(): RevokeKey
+
+    /**
+     * Provide the decryption password for the secret key.
+     *
+     * @param password password
+     * @return builder instance
+     * @throws UnsupportedOption if the implementation does not support key passwords
+     * @throws PasswordNotHumanReadable if the password is not human-readable
+     */
+    @Throws(UnsupportedOption::class, PasswordNotHumanReadable::class)
+    fun withKeyPassword(password: String): RevokeKey =
+        withKeyPassword(password.toByteArray(UTF8Util.UTF8))
+
+    /**
+     * Provide the decryption password for the secret key.
+     *
+     * @param password password
+     * @return builder instance
+     * @throws UnsupportedOption if the implementation does not support key passwords
+     * @throws PasswordNotHumanReadable if the password is not human-readable
+     */
+    @Throws(UnsupportedOption::class, PasswordNotHumanReadable::class)
+    fun withKeyPassword(password: ByteArray): RevokeKey
+
+    fun keys(bytes: ByteArray): Ready = keys(bytes.inputStream())
+
+    fun keys(keys: InputStream): Ready
+}