diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMFallbackCipherState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMFallbackCipherState.kt
index fff41baa..e1357ea9 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMFallbackCipherState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMFallbackCipherState.kt
@@ -172,14 +172,13 @@ internal class AESGCMFallbackCipherState : CipherState {
         ad: ByteArray?, plaintext: ByteArray, plaintextOffset: Int,
         ciphertext: ByteArray, ciphertextOffset: Int, length: Int
     ): Int {
-        val space: Int
         require(!(ciphertextOffset < 0 || ciphertextOffset > ciphertext.size))
         require(!(length < 0 || plaintextOffset < 0 || plaintextOffset > plaintext.size || length > plaintext.size || (plaintext.size - plaintextOffset) < length))
-        space = ciphertext.size - ciphertextOffset
+        val space: Int = ciphertext.size - ciphertextOffset
         if (!haskey) {
             // The key is not set yet - return the plaintext as-is.
             if (length > space) throw ShortBufferException()
-            if (plaintext != ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
+            if (plaintext !== ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
                 plaintext,
                 plaintextOffset,
                 ciphertext,
@@ -219,7 +218,7 @@ internal class AESGCMFallbackCipherState : CipherState {
         if (!haskey) {
             // The key is not set yet - return the ciphertext as-is.
             if (length > space) throw ShortBufferException()
-            if (plaintext != ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
+            if (plaintext !== ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
                 ciphertext,
                 ciphertextOffset,
                 plaintext,
@@ -244,8 +243,7 @@ internal class AESGCMFallbackCipherState : CipherState {
     }
 
     override fun fork(key: ByteArray, offset: Int): CipherState {
-        val cipher: CipherState
-        cipher = AESGCMFallbackCipherState()
+        val cipher: CipherState = AESGCMFallbackCipherState()
         cipher.initializeKey(key, offset)
         return cipher
     }
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMOnCtrCipherState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMOnCtrCipherState.kt
index d68b5d17..1a7175e3 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMOnCtrCipherState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/AESGCMOnCtrCipherState.kt
@@ -45,7 +45,12 @@ import javax.crypto.spec.SecretKeySpec
 internal class AESGCMOnCtrCipherState
 @Throws(NoSuchAlgorithmException::class)
 constructor() : CipherState {
-    private val cipher: Cipher
+    private val cipher: Cipher  = try {
+        Cipher.getInstance("AES/CTR/NoPadding")
+    } catch (e: NoSuchPaddingException) {
+        // AES/CTR is available, but not the unpadded version?  Huh?
+        throw NoSuchAlgorithmException("AES/CTR/NoPadding not available", e)
+    }
     private var keySpec: SecretKeySpec? = null
     private var n: Long = 0
     private val iv: ByteArray = ByteArray(16)
@@ -53,13 +58,6 @@ constructor() : CipherState {
     private val ghash: GHASH = GHASH()
 
     init {
-        cipher = try {
-            Cipher.getInstance("AES/CTR/NoPadding")
-        } catch (e: NoSuchPaddingException) {
-            // AES/CTR is available, but not the unpadded version?  Huh?
-            throw NoSuchAlgorithmException("AES/CTR/NoPadding not available", e)
-        }
-
         // Try to set a 256-bit key on the cipher.  Some JCE's are
         // configured to disallow 256-bit AES if an extra policy
         // file has not been installed.
@@ -85,9 +83,9 @@ constructor() : CipherState {
         val params = IvParameterSpec(iv)
         try {
             cipher.init(Cipher.ENCRYPT_MODE, keySpec, params)
-        } catch (e: InvalidKeyException) {
+        } catch (_: InvalidKeyException) {
             // Shouldn't happen.
-        } catch (e: InvalidAlgorithmParameterException) {
+        } catch (_: InvalidAlgorithmParameterException) {
             // Shouldn't happen.
         }
     }
@@ -196,14 +194,13 @@ constructor() : CipherState {
         ad: ByteArray?, plaintext: ByteArray, plaintextOffset: Int,
         ciphertext: ByteArray, ciphertextOffset: Int, length: Int
     ): Int {
-        val space: Int
         require(!(ciphertextOffset < 0 || ciphertextOffset > ciphertext.size))
         require(!(length < 0 || plaintextOffset < 0 || plaintextOffset > plaintext.size || length > plaintext.size || (plaintext.size - plaintextOffset) < length))
-        space = ciphertext.size - ciphertextOffset
+        val space: Int = ciphertext.size - ciphertextOffset
         if (keySpec == null) {
             // The key is not set yet - return the plaintext as-is.
             if (length > space) throw ShortBufferException()
-            if (plaintext != ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
+            if (plaintext !== ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
                 plaintext,
                 plaintextOffset,
                 ciphertext,
@@ -259,7 +256,7 @@ constructor() : CipherState {
         if (keySpec == null) {
             // The key is not set yet - return the ciphertext as-is.
             if (length > space) throw ShortBufferException()
-            if (plaintext != ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
+            if (plaintext !== ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
                 ciphertext,
                 ciphertextOffset,
                 plaintext,
@@ -281,7 +278,7 @@ constructor() : CipherState {
             throw IllegalStateException(e)
         }
         ghash.update(ciphertext, ciphertextOffset, dataLen)
-        ghash.pad((if (ad != null) ad.size else 0).toLong(), dataLen.toLong())
+        ghash.pad((ad?.size ?: 0).toLong(), dataLen.toLong())
         ghash.finish(iv, 0, 16)
         var temp = 0
         for (index in 0..15) temp =
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/ChaChaPolyCipherState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/ChaChaPolyCipherState.kt
index 10e64d94..9962b5e6 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/ChaChaPolyCipherState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/ChaChaPolyCipherState.kt
@@ -89,7 +89,7 @@ internal class ChaChaPolyCipherState : CipherState {
      */
     private fun finish(ad: ByteArray?, length: Int) {
         poly.pad()
-        putLittleEndian64(polyKey, 0, (if (ad != null) ad.size else 0).toLong())
+        putLittleEndian64(polyKey, 0, (ad?.size ?: 0).toLong())
         putLittleEndian64(polyKey, 8, length.toLong())
         poly.update(polyKey, 0, 16)
         poly.finish(polyKey, 0)
@@ -128,14 +128,13 @@ internal class ChaChaPolyCipherState : CipherState {
         ad: ByteArray?, plaintext: ByteArray, plaintextOffset: Int,
         ciphertext: ByteArray, ciphertextOffset: Int, length: Int
     ): Int {
-        val space: Int
         require(!(ciphertextOffset < 0 || ciphertextOffset > ciphertext.size))
         require(!(length < 0 || plaintextOffset < 0 || plaintextOffset > plaintext.size || length > plaintext.size || (plaintext.size - plaintextOffset) < length))
-        space = ciphertext.size - ciphertextOffset
+        val space: Int = ciphertext.size - ciphertextOffset
         if (!haskey) {
             // The key is not set yet - return the plaintext as-is.
             if (length > space) throw ShortBufferException()
-            if (plaintext != ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
+            if (plaintext !== ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
                 plaintext,
                 plaintextOffset,
                 ciphertext,
@@ -162,16 +161,15 @@ internal class ChaChaPolyCipherState : CipherState {
         plaintextOffset: Int,
         length: Int
     ): Int {
-        var space: Int
         require(!(ciphertextOffset < 0 || ciphertextOffset > ciphertext.size))
-        space = ciphertext.size - ciphertextOffset
+        var space: Int = ciphertext.size - ciphertextOffset
         if (length > space) throw ShortBufferException()
         require(!(length < 0 || plaintextOffset < 0 || plaintextOffset > plaintext.size || length > ciphertext.size || (ciphertext.size - ciphertextOffset) < length))
         space = plaintext.size - plaintextOffset
         if (!haskey) {
             // The key is not set yet - return the ciphertext as-is.
             if (length > space) throw ShortBufferException()
-            if (plaintext != ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
+            if (plaintext !== ciphertext || plaintextOffset != ciphertextOffset) System.arraycopy(
                 ciphertext,
                 ciphertextOffset,
                 plaintext,
@@ -241,21 +239,25 @@ internal class ChaChaPolyCipherState : CipherState {
                 outputOffset += 4
                 length -= 4
             }
-            if (length == 3) {
-                value = block[posn]
-                output[outputOffset] = (input[inputOffset].toInt() xor value).toByte()
-                output[outputOffset + 1] =
-                    (input[inputOffset + 1].toInt() xor (value shr 8)).toByte()
-                output[outputOffset + 2] =
-                    (input[inputOffset + 2].toInt() xor (value shr 16)).toByte()
-            } else if (length == 2) {
-                value = block[posn]
-                output[outputOffset] = (input[inputOffset].toInt() xor value).toByte()
-                output[outputOffset + 1] =
-                    (input[inputOffset + 1].toInt() xor (value shr 8)).toByte()
-            } else if (length == 1) {
-                value = block[posn]
-                output[outputOffset] = (input[inputOffset].toInt() xor value).toByte()
+            when (length) {
+                3 -> {
+                    value = block[posn]
+                    output[outputOffset] = (input[inputOffset].toInt() xor value).toByte()
+                    output[outputOffset + 1] =
+                        (input[inputOffset + 1].toInt() xor (value shr 8)).toByte()
+                    output[outputOffset + 2] =
+                        (input[inputOffset + 2].toInt() xor (value shr 16)).toByte()
+                }
+                2 -> {
+                    value = block[posn]
+                    output[outputOffset] = (input[inputOffset].toInt() xor value).toByte()
+                    output[outputOffset + 1] =
+                        (input[inputOffset + 1].toInt() xor (value shr 8)).toByte()
+                }
+                1 -> {
+                    value = block[posn]
+                    output[outputOffset] = (input[inputOffset].toInt() xor value).toByte()
+                }
             }
         }
 
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve25519DHState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve25519DHState.kt
index 573ff5f9..0f0582a5 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve25519DHState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve25519DHState.kt
@@ -49,21 +49,21 @@ internal class Curve25519DHState : DHState {
     }
 
     override fun getPublicKey(key: ByteArray, offset: Int) {
-        System.arraycopy(publicKey, 0, key, offset, 32)
+        publicKey.copyInto(key, offset, 0, 32)
     }
 
     override fun setPublicKey(key: ByteArray, offset: Int) {
-        System.arraycopy(key, offset, publicKey, 0, 32)
+        key.copyInto(publicKey, 0, offset, offset + 32)
         privateKey.fill(0)
         mode = 0x01
     }
 
     override fun getPrivateKey(key: ByteArray, offset: Int) {
-        System.arraycopy(privateKey, 0, key, offset, 32)
+        privateKey.copyInto(key, offset, 0, 32)
     }
 
     override fun setPrivateKey(key: ByteArray, offset: Int) {
-        System.arraycopy(key, offset, privateKey, 0, 32)
+        key.copyInto(privateKey, 0, offset, offset + 32)
         Curve25519.eval(publicKey, 0, privateKey, null)
         mode = 0x03
     }
@@ -99,8 +99,8 @@ internal class Curve25519DHState : DHState {
     override fun copyFrom(other: DHState) {
         check(other is Curve25519DHState) { "Mismatched DH key objects" }
         if (other === this) return
-        System.arraycopy(other.privateKey, 0, privateKey, 0, 32)
-        System.arraycopy(other.publicKey, 0, publicKey, 0, 32)
+        other.privateKey.copyInto(privateKey, 0, 0, 32)
+        other.publicKey.copyInto(publicKey, 0, 0, 32)
         mode = other.mode
     }
 }
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve448DHState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve448DHState.kt
index c322973f..b61d13a6 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve448DHState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/Curve448DHState.kt
@@ -49,21 +49,21 @@ internal class Curve448DHState : DHState {
     }
 
     override fun getPublicKey(key: ByteArray, offset: Int) {
-        System.arraycopy(publicKey, 0, key, offset, 56)
+        publicKey.copyInto(key, offset, 0, 56)
     }
 
     override fun setPublicKey(key: ByteArray, offset: Int) {
-        System.arraycopy(key, offset, publicKey, 0, 56)
+        key.copyInto(publicKey, 0, offset, offset + 56)
         privateKey.fill(0)
         mode = 0x01
     }
 
     override fun getPrivateKey(key: ByteArray, offset: Int) {
-        System.arraycopy(privateKey, 0, key, offset, 56)
+        privateKey.copyInto(key, offset, 0, 56)
     }
 
     override fun setPrivateKey(key: ByteArray, offset: Int) {
-        System.arraycopy(key, offset, privateKey, 0, 56)
+        key.copyInto(privateKey, 0, offset, offset + 56)
         Curve448.eval(publicKey, 0, privateKey, null)
         mode = 0x03
     }
@@ -99,8 +99,8 @@ internal class Curve448DHState : DHState {
     override fun copyFrom(other: DHState) {
         check(other is Curve448DHState) { "Mismatched DH key objects" }
         if (other === this) return
-        System.arraycopy(other.privateKey, 0, privateKey, 0, 56)
-        System.arraycopy(other.publicKey, 0, publicKey, 0, 56)
+        other.privateKey.copyInto(privateKey, 0, 0, 56)
+        other.publicKey.copyInto(publicKey, 0, 0, 56)
         mode = other.mode
     }
 }
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/HandshakeState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/HandshakeState.kt
index a0dc7cfd..80317871 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/HandshakeState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/HandshakeState.kt
@@ -28,7 +28,6 @@ import com.bitchat.android.noise.southernstorm.protocol.Noise.destroy
 import com.bitchat.android.noise.southernstorm.protocol.Pattern.lookup
 import com.bitchat.android.noise.southernstorm.protocol.Pattern.reverseFlags
 import java.security.NoSuchAlgorithmException
-import java.util.Arrays
 import javax.crypto.BadPaddingException
 import javax.crypto.ShortBufferException
 
@@ -97,8 +96,8 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
      * @return true if a pre-shared key is needed; false if not.
      */
     fun needsPreSharedKey(): Boolean {
-        if (preSharedKey != null) return false
-        else return (requirements and PSK_REQUIRED) != 0
+        return if (preSharedKey != null) false
+        else (requirements and PSK_REQUIRED) != 0
     }
 
     /**
@@ -168,8 +167,8 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
      * will return false.
      */
     fun needsLocalKeyPair(): Boolean {
-        if (localKeyPair != null) return !localKeyPair!!.hasPrivateKey()
-        else return false
+        return if (localKeyPair != null) !localKeyPair!!.hasPrivateKey()
+        else false
     }
 
     /**
@@ -180,8 +179,8 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
      * false if not.
      */
     fun hasLocalKeyPair(): Boolean {
-        if (localKeyPair != null) return localKeyPair!!.hasPrivateKey()
-        else return false
+        return if (localKeyPair != null) localKeyPair!!.hasPrivateKey()
+        else false
     }
 
     /**
@@ -193,8 +192,8 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
      * will return false.
      */
     fun needsRemotePublicKey(): Boolean {
-        if (remotePublicKey != null) return !remotePublicKey!!.hasPublicKey()
-        else return false
+        return if (remotePublicKey != null) !remotePublicKey!!.hasPublicKey()
+        else false
     }
 
     /**
@@ -205,8 +204,8 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
      * false if not.
      */
     fun hasRemotePublicKey(): Boolean {
-        if (remotePublicKey != null) return remotePublicKey!!.hasPublicKey()
-        else return false
+        return if (remotePublicKey != null) remotePublicKey!!.hasPublicKey()
+        else false
     }
 
     val fixedEphemeralKey: DHState?
@@ -227,7 +226,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
             try {
                 fixedEphemeral =
                     createDH(localEphemeral!!.dhName)
-            } catch (e: NoSuchAlgorithmException) {
+            } catch (_: NoSuchAlgorithmException) {
                 // This shouldn't happen - the local ephemeral key would
                 // have already been created with the same name!
                 fixedEphemeral = null
@@ -253,7 +252,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
             try {
                 fixedHybrid =
                     createDH(localHybrid!!.dhName)
-            } catch (e: NoSuchAlgorithmException) {
+            } catch (_: NoSuchAlgorithmException) {
                 // This shouldn't happen - the local hybrid key would
                 // have already been created with the same name!
                 fixedHybrid = null
@@ -320,21 +319,21 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
         if ((flags.toInt() and Pattern.FLAG_LOCAL_EPHEMERAL.toInt()) != 0) localEphemeral =
             createDH(dh)
         if ((flags.toInt() and Pattern.FLAG_LOCAL_HYBRID.toInt()) != 0) localHybrid =
-            Noise.createDH(hybrid!!)
+            createDH(hybrid!!)
         if ((flags.toInt() and Pattern.FLAG_REMOTE_STATIC.toInt()) != 0) remotePublicKey =
             createDH(dh)
         if ((flags.toInt() and Pattern.FLAG_REMOTE_EPHEMERAL.toInt()) != 0) remoteEphemeral =
             createDH(dh)
         if ((flags.toInt() and Pattern.FLAG_REMOTE_HYBRID.toInt()) != 0) remoteHybrid =
-            Noise.createDH(hybrid!!)
+            createDH(hybrid!!)
 
 
         // We cannot use hybrid algorithms like New Hope for ephemeral or static keys,
         // as the unbalanced nature of the algorithm only works with "f" and "ff" tokens.
-        if (localKeyPair is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '" + localKeyPair!!.dhName + "' for static keys")
-        if (localEphemeral is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '" + localEphemeral!!.dhName + "' for ephemeral keys")
-        if (remotePublicKey is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '" + remotePublicKey!!.dhName + "' for static keys")
-        if (remoteEphemeral is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '" + remoteEphemeral!!.dhName + "' for ephemeral keys")
+        if (localKeyPair is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '${localKeyPair!!.dhName}' for static keys")
+        if (localEphemeral is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '${localEphemeral!!.dhName}' for ephemeral keys")
+        if (remotePublicKey is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '${remotePublicKey!!.dhName}' for static keys")
+        if (remoteEphemeral is DHStateHybrid) throw NoSuchAlgorithmException("Cannot use '${remoteEphemeral!!.dhName}' for ephemeral keys")
     }
 
     /**
@@ -379,9 +378,9 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
 
         // Log the symmetric state BEFORE any mixing operations (matching iOS)
         Log.d(TAG, "=== ANDROID HANDSHAKE START - INITIAL STATE ===")
-        Log.d(TAG, "Protocol: " + symmetric!!.protocolName)
-        Log.d(TAG, "Role: " + (if (isInitiator) "INITIATOR" else "RESPONDER"))
-        Log.d(TAG, "Initial symmetric hash: " + bytesToHex(symmetric!!.handshakeHash!!))
+        Log.d(TAG, "Protocol: ${symmetric!!.protocolName}")
+        Log.d(TAG, "Role: ${if (isInitiator) "INITIATOR" else "RESPONDER"}")
+        Log.d(TAG, "Initial symmetric hash: ${bytesToHex(symmetric!!.handshakeHash!!)}")
 
 
         // Hash the prologue value.
@@ -389,7 +388,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
         val p = prologue
         if (p != null) symmetric!!.mixHash(p, 0, p.size)
         else symmetric!!.mixHash(emptyPrologue, 0, 0)
-        Log.d(TAG, "Hash after empty prologue: " + bytesToHex(symmetric!!.handshakeHash!!))
+        Log.d(TAG, "Hash after empty prologue: ${bytesToHex(symmetric!!.handshakeHash!!)}")
 
 
         // Hash the pre-shared key into the chaining key and handshake hash.
@@ -421,13 +420,12 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
         Log.d(TAG, "=== ANDROID HANDSHAKE START - FINAL STATE ===")
         Log.d(
             TAG,
-            "Final symmetric hash after mixPreMessageKeys(): " + bytesToHex(symmetric!!.handshakeHash!!)
+            "Final symmetric hash after mixPreMessageKeys(): ${bytesToHex(symmetric!!.handshakeHash!!)}"
         )
         Log.d(TAG, "===========================================")
 
         // The handshake has officially started - set the first action.
-        if (isInitiator) action = WRITE_MESSAGE
-        else action = READ_MESSAGE
+        action = if (isInitiator) WRITE_MESSAGE else READ_MESSAGE
     }
 
     /**
@@ -579,7 +577,6 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
      * @param remote Remote public key object.
      */
     private fun mixDH(local: DHState, remote: DHState) {
-        check(!(local == null || remote == null)) { "Pattern definition error" }
         val len = local.sharedKeyLength
         val shared = ByteArray(len)
         try {
@@ -750,7 +747,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
                     else -> {
                         // Unknown token code.  Abort.
                         throw IllegalStateException(
-                            "Unknown handshake token " + token.toInt().toString()
+                            "Unknown handshake token ${token.toInt()}"
                         )
                     }
                 }
@@ -777,7 +774,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
             // If we failed, then clear any sensitive data that may have
             // already been written to the message buffer.
             if (!success) {
-                Arrays.fill(message, messageOffset, message.size - messageOffset, 0.toByte())
+                message.fill(0, messageOffset, message.size - messageOffset)
                 action = FAILED
             }
         }
@@ -817,7 +814,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
         payload: ByteArray,
         payloadOffset: Int
     ): Int {
-        var messageOffset = messageOffset
+        @Suppress("NAME_SHADOWING") var messageOffset = messageOffset
         var success = false
         val messageEnd = messageOffset + messageLength
 
@@ -955,7 +952,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
                     else -> {
                         // Unknown token code.  Abort.
                         throw IllegalStateException(
-                            "Unknown handshake token " + token.toInt().toString()
+                            "Unknown handshake token ${token.toInt()}"
                         )
                     }
                 }
@@ -976,7 +973,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
             // If we failed, then clear any sensitive data that may have
             // already been written to the payload buffer.
             if (!success) {
-                Arrays.fill(payload, payloadOffset, payload.size - payloadOffset, 0.toByte())
+                payload.fill(0, payloadOffset, payload.size - payloadOffset)
                 action = FAILED
             }
         }
@@ -1143,7 +1140,7 @@ class HandshakeState(protocolName: String, role: Int) : Destroyable {
         private fun bytesToHex(bytes: ByteArray): String {
             val sb = StringBuilder()
             for (b in bytes) {
-                sb.append(String.format("%02x", b))
+                sb.append("%02x".format(b))
             }
             return sb.toString()
         }
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/NewHopeDHState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/NewHopeDHState.kt
index 85e489ef..a5b9c586 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/NewHopeDHState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/NewHopeDHState.kt
@@ -48,7 +48,7 @@ internal class NewHopeDHState : DHStateHybrid {
      */
     private inner class NewHopeWithPrivateKey(private val randomData: ByteArray) : NewHopeTor() {
         override fun randombytes(buffer: ByteArray) {
-            System.arraycopy(randomData, 0, buffer, 0, buffer.size)
+            randomData.copyInto(buffer, 0, 0, buffer.size)
         }
     }
 
@@ -102,21 +102,19 @@ internal class NewHopeDHState : DHStateHybrid {
 
     override fun getPublicKey(key: ByteArray, offset: Int) {
         val pk = publicKey
-        if (pk != null) System.arraycopy(pk, 0, key, offset, publicKeyLength)
+        if (pk != null) pk.copyInto(key, offset, 0, publicKeyLength)
         else key.fill(0, offset, offset + publicKeyLength)
     }
 
     override fun setPublicKey(key: ByteArray, offset: Int) {
         publicKey?.let { Noise.destroy(it) }
         val len = publicKeyLength
-        val pk = ByteArray(len)
-        System.arraycopy(key, offset, pk, 0, len)
-        publicKey = pk
+        publicKey = key.copyOfRange(offset, offset + len)
     }
 
     override fun getPrivateKey(key: ByteArray, offset: Int) {
         val sk = privateKey
-        if (sk != null) System.arraycopy(sk, 0, key, offset, privateKeyLength)
+        if (sk != null) sk.copyInto(key, offset, 0, privateKeyLength)
         else key.fill(0, offset, offset + privateKeyLength)
     }
 
@@ -125,9 +123,7 @@ internal class NewHopeDHState : DHStateHybrid {
         // Guess the key type from the length of the test data.
         keyType = if (offset == 0 && key.size == 64) KeyType.AlicePrivate else KeyType.BobPrivate
         val len = privateKeyLength
-        val sk = ByteArray(len)
-        System.arraycopy(key, offset, sk, 0, len)
-        privateKey = sk
+        privateKey = key.copyOfRange(offset, offset + len)
     }
 
     override fun setToNullPublicKey() {
@@ -169,7 +165,7 @@ internal class NewHopeDHState : DHStateHybrid {
             }
             KeyType.BobCalculated -> {
                 // The shared key for Bob was already computed when the key was generated.
-                System.arraycopy(privateKey!!, 0, sharedKey, 0, NewHope.SHAREDBYTES)
+                privateKey!!.copyInto(sharedKey, 0, 0, NewHope.SHAREDBYTES)
             }
             else -> throw IllegalStateException("Cannot calculate with this DH object")
         }
diff --git a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/SymmetricState.kt b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/SymmetricState.kt
index 4c2ac2de..4a8f8878 100644
--- a/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/SymmetricState.kt
+++ b/app/src/main/java/com/bitchat/android/noise/southernstorm/protocol/SymmetricState.kt
@@ -28,7 +28,6 @@ import com.bitchat.android.noise.southernstorm.protocol.Noise.destroy
 import java.io.UnsupportedEncodingException
 import java.security.DigestException
 import java.security.MessageDigest
-import java.util.Arrays
 import javax.crypto.BadPaddingException
 import javax.crypto.ShortBufferException
 
@@ -57,7 +56,7 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
      */
     var handshakeHash: ByteArray?
         private set
-    private var prev_h: ByteArray?
+    private var prevH: ByteArray?
 
     /**
      * Constructs a new symmetric state object.
@@ -73,50 +72,38 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
         this.protocolName = protocolName
         cipher = createCipher(cipherName)
         hash = createHash(hashName)
-        val hashLength = hash!!.getDigestLength()
+        val hashLength = hash!!.digestLength
         ck = ByteArray(hashLength)
-        this.handshakeHash = ByteArray(hashLength)
-        prev_h = ByteArray(hashLength)
+        val initialHash = ByteArray(hashLength)
+        this.handshakeHash = initialHash
+        prevH = ByteArray(hashLength)
 
-        val protocolNameBytes: ByteArray
-        try {
-            protocolNameBytes = protocolName.toByteArray(charset("UTF-8"))
-        } catch (e: UnsupportedEncodingException) {
+        val protocolNameBytes: ByteArray = try {
+            protocolName.toByteArray(charset("UTF-8"))
+        } catch (_: UnsupportedEncodingException) {
             // If UTF-8 is not supported, then we are definitely in trouble!
             throw UnsupportedOperationException("UTF-8 encoding is not supported")
         }
 
         if (protocolNameBytes.size <= hashLength) {
-            System.arraycopy(
-                protocolNameBytes, 0,
-                this.handshakeHash, 0, protocolNameBytes.size
-            )
-            Arrays.fill(
-                this.handshakeHash,
-                protocolNameBytes.size,
-                handshakeHash!!.size,
-                0.toByte()
-            )
+            protocolNameBytes.copyInto(initialHash, 0, 0, protocolNameBytes.size)
+            initialHash.fill(0, protocolNameBytes.size, initialHash.size)
         } else {
             hashOne(
                 protocolNameBytes, 0, protocolNameBytes.size,
-                this.handshakeHash!!, 0, handshakeHash!!.size
+                initialHash, 0, initialHash.size
             )
         }
 
-        System.arraycopy(this.handshakeHash, 0, ck, 0, hashLength)
+        initialHash.copyInto(ck!!, 0, 0, hashLength)
 
 
         // LOGGING: Initial symmetric state after protocol name initialization (matching iOS)
         Log.d(TAG, "=== ANDROID SYMMETRIC STATE INITIALIZED ===")
-        Log.d(TAG, "Protocol: " + protocolName)
-        Log.d(
-            TAG, "Initial hash (h): " + Companion.bytesToHex(
-                this.handshakeHash!!
-            )
-        )
-        Log.d(TAG, "Initial chaining key (ck): " + Companion.bytesToHex(ck!!))
-        Log.d(TAG, "Hash length: " + handshakeHash!!.size)
+        Log.d(TAG, "Protocol: $protocolName")
+        Log.d(TAG, "Initial hash (h): " + bytesToHex(initialHash))
+        Log.d(TAG, "Initial chaining key (ck): " + bytesToHex(ck!!))
+        Log.d(TAG, "Hash length: " + initialHash.size)
         Log.d(TAG, "=========================================")
     }
 
@@ -137,15 +124,11 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
     fun mixKey(data: ByteArray, offset: Int, length: Int) {
         // LOGGING: Before mixKey operation (matching iOS)
         val inputData = ByteArray(length)
-        System.arraycopy(data, offset, inputData, 0, length)
+        data.copyInto(inputData, 0, offset, offset + length)
         Log.d(TAG, "*** Android mixKey() BEFORE ***")
-        Log.d(TAG, "Input data (" + length + " bytes): " + bytesToHex(inputData))
-        Log.d(TAG, "Current CK: " + Companion.bytesToHex(ck!!))
-        Log.d(
-            TAG, "Current Hash: " + Companion.bytesToHex(
-                this.handshakeHash!!
-            )
-        )
+        Log.d(TAG, "Input data ($length bytes): " + bytesToHex(inputData))
+        Log.d(TAG, "Current CK: " + bytesToHex(ck!!))
+        Log.d(TAG, "Current Hash: " + bytesToHex(this.handshakeHash!!))
 
         val keyLength = cipher!!.keyLength
         val tempKey = ByteArray(keyLength)
@@ -172,12 +155,8 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
 
         // LOGGING: After mixKey operation (matching iOS)
         Log.d(TAG, "*** Android mixKey() AFTER ***")
-        Log.d(TAG, "New CK: " + Companion.bytesToHex(ck!!))
-        Log.d(
-            TAG, "Hash unchanged: " + Companion.bytesToHex(
-                this.handshakeHash!!
-            )
-        )
+        Log.d(TAG, "New CK: " + bytesToHex(ck!!))
+        Log.d(TAG, "Hash unchanged: " + bytesToHex(this.handshakeHash!!))
         Log.d(TAG, "Cipher now has key: " + (cipher!!.macLength > 0))
     }
 
@@ -191,28 +170,21 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
     fun mixHash(data: ByteArray, offset: Int, length: Int) {
         // LOGGING: Before mixHash operation (matching iOS)
         val inputData = ByteArray(length)
-        System.arraycopy(data, offset, inputData, 0, length)
+        data.copyInto(inputData, 0, offset, offset + length)
         Log.d(TAG, "*** Android mixHash() BEFORE ***")
-        Log.d(TAG, "Input data (" + length + " bytes): " + bytesToHex(inputData))
-        Log.d(
-            TAG, "Current Hash: " + Companion.bytesToHex(
-                this.handshakeHash!!
-            )
-        )
+        Log.d(TAG, "Input data ($length bytes): " + bytesToHex(inputData))
+        Log.d(TAG, "Current Hash: " + bytesToHex(this.handshakeHash!!))
 
+        val h = handshakeHash!!
         hashTwo(
-            this.handshakeHash!!, 0, handshakeHash!!.size, data, offset, length,
-            this.handshakeHash!!, 0, handshakeHash!!.size
+            h, 0, h.size, data, offset, length,
+            h, 0, h.size
         )
 
 
         // LOGGING: After mixHash operation (matching iOS)
         Log.d(TAG, "*** Android mixHash() AFTER ***")
-        Log.d(
-            TAG, "New Hash: " + Companion.bytesToHex(
-                this.handshakeHash!!
-            )
-        )
+        Log.d(TAG, "New Hash: " + bytesToHex(this.handshakeHash!!))
     }
 
     /**
@@ -221,7 +193,7 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
      * @param key The pre-shared key value.
      */
     fun mixPreSharedKey(key: ByteArray) {
-        val temp = ByteArray(hash!!.getDigestLength())
+        val temp = ByteArray(hash!!.digestLength)
         try {
             hkdf(ck!!, 0, ck!!.size, key, 0, key.size, ck!!, 0, ck!!.size, temp, 0, temp.size)
             mixHash(temp, 0, temp.size)
@@ -333,10 +305,11 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
         plaintextOffset: Int,
         length: Int
     ): Int {
-        System.arraycopy(this.handshakeHash, 0, prev_h, 0, handshakeHash!!.size)
+        val h = handshakeHash!!
+        h.copyInto(prevH!!, 0, 0, h.size)
         mixHash(ciphertext, ciphertextOffset, length)
         return cipher!!.decryptWithAd(
-            prev_h,
+            prevH,
             ciphertext,
             ciphertextOffset,
             plaintext,
@@ -348,20 +321,15 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
     /**
      * Splits the symmetric state into two ciphers for session encryption,
      * and optionally mixes in a secondary symmetric key.
-     * 
+     *
      * @param secondaryKey The buffer containing the secondary key.
      * @param offset The offset of the first secondary key byte.
      * @param length The length of the secondary key in bytes, which
      * must be either 0 or 32.
      * @return The pair of ciphers for sending and receiving.
-     * 
+     *
      * @throws IllegalArgumentException The length is not 0 or 32.
      */
-    /**
-     * Splits the symmetric state into two ciphers for session encryption.
-     * 
-     * @return The pair of ciphers for sending and receiving.
-     */
     @JvmOverloads
     fun split(
         secondaryKey: ByteArray? = ByteArray(0),
@@ -388,8 +356,8 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
                 if (c1 == null || c2 == null || pair == null) {
                     // Could not create some of the objects.  Clean up the others
                     // to avoid accidental leakage of k1 or k2.
-                    if (c1 != null) c1.destroy()
-                    if (c2 != null) c2.destroy()
+                    c1?.destroy()
+                    c2?.destroy()
                     pair = null
                 }
             }
@@ -420,9 +388,9 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
             Noise.destroy(this.handshakeHash!!)
             this.handshakeHash = null
         }
-        if (prev_h != null) {
-            Noise.destroy(prev_h!!)
-            prev_h = null
+        if (prevH != null) {
+            Noise.destroy(prevH!!)
+            prevH = null
         }
     }
 
@@ -450,8 +418,8 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
         hash!!.update(data, offset, length)
         try {
             hash!!.digest(output, outputOffset, outputLength)
-        } catch (e: DigestException) {
-            Arrays.fill(output, outputOffset, outputLength, 0.toByte())
+        } catch (_: DigestException) {
+            output.fill(0, outputOffset, outputLength)
         }
     }
 
@@ -480,8 +448,8 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
         hash!!.update(data2, offset2, length2)
         try {
             hash!!.digest(output, outputOffset, outputLength)
-        } catch (e: DigestException) {
-            Arrays.fill(output, outputOffset, outputLength, 0.toByte())
+        } catch (_: DigestException) {
+            output.fill(0, outputOffset, outputLength)
         }
     }
 
@@ -505,19 +473,18 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
     ) {
         // In all of the algorithms of interest to us, the block length
         // is twice the size of the hash length.
-        val hashLength = hash!!.getDigestLength()
+        val hashLength = hash!!.digestLength
         val blockLength = hashLength * 2
         val block = ByteArray(blockLength)
-        var index: Int
         try {
             if (keyLength <= blockLength) {
                 System.arraycopy(key, keyOffset, block, 0, keyLength)
-                Arrays.fill(block, keyLength, blockLength, 0.toByte())
+                block.fill(0, keyLength, blockLength)
             } else {
                 hash!!.reset()
                 hash!!.update(key, keyOffset, keyLength)
                 hash!!.digest(block, 0, hashLength)
-                Arrays.fill(block, hashLength, blockLength, 0.toByte())
+                block.fill(0, hashLength, blockLength)
             }
             for (i in 0 until blockLength) {
                 block[i] = (block[i].toInt() xor 0x36).toByte()
@@ -533,8 +500,8 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
             hash!!.update(block, 0, blockLength)
             hash!!.update(output, outputOffset, hashLength)
             hash!!.digest(output, outputOffset, outputLength)
-        } catch (e: DigestException) {
-            Arrays.fill(output, outputOffset, outputLength, 0.toByte())
+        } catch (_: DigestException) {
+            output.fill(0, outputOffset, outputLength)
         } finally {
             destroy(block)
         }
@@ -564,7 +531,7 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
         output1: ByteArray, output1Offset: Int, output1Length: Int,
         output2: ByteArray, output2Offset: Int, output2Length: Int
     ) {
-        val hashLength = hash!!.getDigestLength()
+        val hashLength = hash!!.digestLength
         val tempKey = ByteArray(hashLength)
         val tempHash = ByteArray(hashLength + 1)
         try {
@@ -590,7 +557,7 @@ internal class SymmetricState(protocolName: String, cipherName: String, hashName
         private fun bytesToHex(bytes: ByteArray): String {
             val sb = StringBuilder()
             for (b in bytes) {
-                sb.append(String.format("%02x", b))
+                sb.append("%02x".format(b))
             }
             return sb.toString()
         }