diff --git a/src/main/java/swiss/qpq/gajumaru/core/crypto/Blake2b.java b/src/main/java/swiss/qpq/gajumaru/core/crypto/Blake2b.java
index 330b73f..2343481 100644
--- a/src/main/java/swiss/qpq/gajumaru/core/crypto/Blake2b.java
+++ b/src/main/java/swiss/qpq/gajumaru/core/crypto/Blake2b.java
@@ -21,7 +21,6 @@
 package swiss.qpq.gajumaru.core.crypto;
 
 import java.util.Arrays;
-import swiss.qpq.gajumaru.core.tools.CryptoUtils;
 
 
 // Pure Java implementation of BLAKE2b.
diff --git a/src/main/java/swiss/qpq/gajumaru/core/crypto/Keccak256.java b/src/main/java/swiss/qpq/gajumaru/core/crypto/Keccak256.java
index dd5eb33..b628919 100644
--- a/src/main/java/swiss/qpq/gajumaru/core/crypto/Keccak256.java
+++ b/src/main/java/swiss/qpq/gajumaru/core/crypto/Keccak256.java
@@ -29,7 +29,6 @@ import swiss.qpq.gajumaru.core.tools.CryptoUtils;
 
 public final class Keccak256 {
 
-    private static final int LANE_SIZE = 64;
     private static final int STATE_SIZE = 25;
     private static final int CAPACITY = 512;
     private static final int BITRATE = 1600 - CAPACITY; // 1088 bits = 136 bytes
diff --git a/src/main/java/swiss/qpq/gajumaru/core/crypto/Vault.java b/src/main/java/swiss/qpq/gajumaru/core/crypto/Vault.java
index c1470da..63b7895 100644
--- a/src/main/java/swiss/qpq/gajumaru/core/crypto/Vault.java
+++ b/src/main/java/swiss/qpq/gajumaru/core/crypto/Vault.java
@@ -40,18 +40,7 @@ public final class Vault {
     /**
      * Holds the results of an encryption operation.
      */
-    public static final class Ciphertext {
-        private final byte[] iv;
-        private final byte[] data;
-
-        public Ciphertext(byte[] iv, byte[] data) {
-            this.iv = iv;
-            this.data = data;
-        }
-
-        public byte[] getIv() { return iv; }
-        public byte[] getData() { return data; }
-    }
+    public record Ciphertext(byte[] iv, byte[] data) {}
 
     /**
      * Encrypts plaintext using AES/GCM.