diff --git a/NDecrypt.Core/ITool.cs b/NDecrypt.Core/ITool.cs
index edff870..ee526a8 100644
--- a/NDecrypt.Core/ITool.cs
+++ b/NDecrypt.Core/ITool.cs
@@ -5,15 +5,17 @@
         /// <summary>
         /// Attempts to encrypt an input file
         /// </summary>
+        /// <param name="filename">Name of the file to encrypt</param>
         /// <param name="force">Indicates if the operation should be forced</param>
         /// <returns>True if the file could be encrypted, false otherwise</returns>
-        bool EncryptFile(bool force);
+        bool EncryptFile(string filename, bool force);
 
         /// <summary>
         /// Attempts to decrypt an input file
         /// </summary>
+        /// <param name="filename">Name of the file to decrypt</param>
         /// <param name="force">Indicates if the operation should be forced</param>
         /// <returns>True if the file could be decrypted, false otherwise</returns>
-        bool DecryptFile(bool force);
+        bool DecryptFile(string filename, bool force);
     }
 }
diff --git a/NDecrypt.N3DS/CIATool.cs b/NDecrypt.N3DS/CIATool.cs
index 14d4772..e427966 100644
--- a/NDecrypt.N3DS/CIATool.cs
+++ b/NDecrypt.N3DS/CIATool.cs
@@ -14,11 +14,6 @@ namespace NDecrypt.N3DS
     // https://www.3dbrew.org/wiki/CIA
     public class CIATool : ITool
     {
-        /// <summary>
-        /// Name of the input CIA file
-        /// </summary>
-        private readonly string filename;
-
         /// <summary>
         /// Decryption args to use while processing
         /// </summary>
@@ -49,26 +44,27 @@ namespace NDecrypt.N3DS
         /// </summary>
         private readonly BigInteger[] NormalKey2C = new BigInteger[8];
 
-        public CIATool(string filename, DecryptArgs decryptArgs)
+        public CIATool(DecryptArgs decryptArgs)
         {
-            this.filename = filename;
             this.decryptArgs = decryptArgs;
         }
 
         #region Common Methods
 
         /// <inheritdoc/>
-        public bool EncryptFile(bool force) => ProcessFile(encrypt: true, force);
+        public bool EncryptFile(string filename, bool force)
+            => ProcessFile(filename, encrypt: true, force);
 
         /// <inheritdoc/>
-        public bool DecryptFile(bool force) => ProcessFile(encrypt: false, force);
+        public bool DecryptFile(string filename, bool force)
+            => ProcessFile(filename, encrypt: false, force);
 
         /// <summary>
         /// Process an input file given the input values
         /// </summary>
         /// <param name="encrypt">Indicates if the file should be encrypted or decrypted</param>
         /// <param name="force">Indicates if the operation should be forced</param>
-        private bool ProcessFile(bool encrypt, bool force)
+        private bool ProcessFile(string filename, bool encrypt, bool force)
         {
             // Ensure the constants are all set
             if (decryptArgs.IsReady != true)
diff --git a/NDecrypt.N3DS/ThreeDSTool.cs b/NDecrypt.N3DS/ThreeDSTool.cs
index 9a435ca..1973c1e 100644
--- a/NDecrypt.N3DS/ThreeDSTool.cs
+++ b/NDecrypt.N3DS/ThreeDSTool.cs
@@ -12,11 +12,6 @@ namespace NDecrypt.N3DS
 {
     public class ThreeDSTool : ITool
     {
-        /// <summary>
-        /// Name of the input 3DS file
-        /// </summary>
-        private readonly string filename;
-
         /// <summary>
         /// Decryption args to use while processing
         /// </summary>
@@ -47,26 +42,27 @@ namespace NDecrypt.N3DS
         /// </summary>
         private readonly BigInteger[] NormalKey2C = new BigInteger[8];
 
-        public ThreeDSTool(string filename, DecryptArgs decryptArgs)
+        public ThreeDSTool(DecryptArgs decryptArgs)
         {
-            this.filename = filename;
             this.decryptArgs = decryptArgs;
         }
 
         #region Common Methods
 
         /// <inheritdoc/>
-        public bool EncryptFile(bool force) => ProcessFile(encrypt: true, force);
+        public bool EncryptFile(string filename, bool force)
+            => ProcessFile(filename, encrypt: true, force);
 
         /// <inheritdoc/>
-        public bool DecryptFile(bool force) => ProcessFile(encrypt: false, force);
+        public bool DecryptFile(string filename, bool force)
+            => ProcessFile(filename, encrypt: false, force);
 
         /// <summary>
         /// Process an input file given the input values
         /// </summary>
         /// <param name="encrypt">Indicates if the file should be encrypted or decrypted</param>
         /// <param name="force">Indicates if the operation should be forced</param>
-        private bool ProcessFile(bool encrypt, bool force)
+        private bool ProcessFile(string filename, bool encrypt, bool force)
         {
             // Ensure the constants are all set
             if (decryptArgs.IsReady != true)
diff --git a/NDecrypt.Nitro/DSTool.cs b/NDecrypt.Nitro/DSTool.cs
index f85432f..57cd905 100644
--- a/NDecrypt.Nitro/DSTool.cs
+++ b/NDecrypt.Nitro/DSTool.cs
@@ -10,11 +10,6 @@ namespace NDecrypt.Nitro
 {
     public class DSTool : ITool
     {
-        /// <summary>
-        /// Name of the input DS/DSi file
-        /// </summary>
-        private readonly string filename;
-
         #region Encryption process variables
 
         private uint[] _cardHash = new uint[0x412];
@@ -22,15 +17,12 @@ namespace NDecrypt.Nitro
 
         #endregion
 
-        public DSTool(string filename, DecryptArgs decryptArgs)
-        {
-            this.filename = filename;
-        }
+        public DSTool() { }
 
         #region Encrypt
 
         /// <inheritdoc/>
-        public bool EncryptFile(bool force)
+        public bool EncryptFile(string filename, bool force)
         {
             try
             {
@@ -46,6 +38,10 @@ namespace NDecrypt.Nitro
                     return false;
                 }
 
+                // Reset state variables
+                _cardHash = new uint[0x412];
+                _arg2 = new uint[3];
+
                 // Encrypt the secure area
                 EncryptSecureArea(cart, force, reader, writer);
                 return true;
@@ -180,7 +176,7 @@ namespace NDecrypt.Nitro
         #region Decrypt
 
         /// <inheritdoc/>
-        public bool DecryptFile(bool force)
+        public bool DecryptFile(string filename, bool force)
         {
             try
             {
@@ -189,13 +185,17 @@ namespace NDecrypt.Nitro
                 using var writer = File.Open(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
 
                 // Deserialize the cart information
-                Cart? cart = NitroDeserializer.DeserializeStream(reader);
+                var cart = NitroDeserializer.DeserializeStream(reader);
                 if (cart == null)
                 {
                     Console.WriteLine("Error: Not a DS or DSi Rom!");
                     return false;
                 }
 
+                // Reset state variables
+                _cardHash = new uint[0x412];
+                _arg2 = new uint[3];
+
                 // Decrypt the secure area
                 DecryptSecureArea(cart, force, reader, writer);
 
diff --git a/NDecrypt/Program.cs b/NDecrypt/Program.cs
index a83bc5e..65733cf 100644
--- a/NDecrypt/Program.cs
+++ b/NDecrypt/Program.cs
@@ -150,12 +150,12 @@ namespace NDecrypt
             if (tool == null)
                 return;
 
-            if (encrypt && !tool.EncryptFile(force))
+            if (encrypt && !tool.EncryptFile(path, force))
             {
                 Console.WriteLine("Encryption failed!");
                 return;
             }
-            else if (!encrypt && !tool.DecryptFile(force))
+            else if (!encrypt && !tool.DecryptFile(path, force))
             {
                 Console.WriteLine("Decryption failed!");
                 return;
@@ -204,19 +204,19 @@ More than one path can be specified at a time.");
             {
                 case FileType.NDS:
                     Console.WriteLine("File recognized as Nintendo DS");
-                    return new DSTool(filename, decryptArgs);
+                    return new DSTool();
                 case FileType.NDSi:
                     Console.WriteLine("File recognized as Nintendo DS");
-                    return new DSTool(filename, decryptArgs);
+                    return new DSTool();
                 case FileType.iQueDS:
                     Console.WriteLine("File recognized as iQue DS");
-                    return new DSTool(filename, decryptArgs);
+                    return new DSTool();
                 case FileType.N3DS:
                     Console.WriteLine("File recognized as Nintendo 3DS");
-                    return new ThreeDSTool(filename, decryptArgs);
+                    return new ThreeDSTool(decryptArgs);
                 case FileType.N3DSCIA:
                     Console.WriteLine("File recognized as Nintendo 3DS CIA [CAUTION: NOT WORKING CURRENTLY]");
-                    return new CIATool(filename, decryptArgs);
+                    return new CIATool(decryptArgs);
                 case FileType.NULL:
                 default:
                     Console.WriteLine($"Unrecognized file format for {filename}. Expected *.nds, *.nds.enc, *.srl, *.dsi, *.3ds");