diff --git a/NDecrypt.Core/CommonOperations.cs b/NDecrypt.Core/CommonOperations.cs
index 73e5bd0..2ce0d35 100644
--- a/NDecrypt.Core/CommonOperations.cs
+++ b/NDecrypt.Core/CommonOperations.cs
@@ -19,7 +19,10 @@ namespace NDecrypt.Core
         /// <returns>Initialized AES cipher</returns>
         public static IBufferedCipher CreateAESDecryptionCipher(byte[] key, byte[] iv)
         {
-            var keyParam = new KeyParameter(TakeSixteen(key));
+            if (key.Length != 16)
+                throw new ArgumentOutOfRangeException(nameof(key));
+
+            var keyParam = new KeyParameter(key);
             var cipher = CipherUtilities.GetCipher("AES/CTR");
             cipher.Init(forEncryption: false, new ParametersWithIV(keyParam, iv));
             return cipher;
@@ -33,7 +36,10 @@ namespace NDecrypt.Core
         /// <returns>Initialized AES cipher</returns>
         public static IBufferedCipher CreateAESEncryptionCipher(byte[] key, byte[] iv)
         {
-            var keyParam = new KeyParameter(TakeSixteen(key));
+            if (key.Length != 16)
+                throw new ArgumentOutOfRangeException(nameof(key));
+
+            var keyParam = new KeyParameter(key);
             var cipher = CipherUtilities.GetCipher("AES/CTR");
             cipher.Init(forEncryption: true, new ParametersWithIV(keyParam, iv));
             return cipher;
@@ -118,18 +124,6 @@ namespace NDecrypt.Core
             progress($"{blockCount + 1} / {blockCount + 1} MB... Done!\r\n");
         }
 
-        /// <summary>
-        /// Pad an array to 16 bytes
-        /// </summary>
-        /// <param name="input">Byte array value to pad</param>
-        /// <returns>16-byte padded array</returns>
-        internal static byte[] TakeSixteen(byte[] input)
-        {
-            var arr = new byte[16];
-            Array.Copy(input, arr, Math.Min(input.Length, 16));
-            return arr;
-        }
-
         #endregion
 
         #region Byte Arrays
diff --git a/NDecrypt.Core/PartitionKeys.cs b/NDecrypt.Core/PartitionKeys.cs
index 8b84b4f..605dc83 100644
--- a/NDecrypt.Core/PartitionKeys.cs
+++ b/NDecrypt.Core/PartitionKeys.cs
@@ -55,10 +55,7 @@ namespace NDecrypt.Core
             KeyX2C = development ? args.DevKeyX0x2C : args.KeyX0x2C;
 
             // Backup headers can't have a KeyY value set
-            if (signature != null)
-                KeyY = TakeSixteen(signature);
-            else
-                KeyY = TakeSixteen(new byte[16]);
+            KeyY = signature != null && signature.Length == 16 ? signature : new byte[16];
 
             // Set the standard normal key values
             NormalKey = new byte[16];