diff --git a/CASA/micasad/lss/CASACrypto.cs b/CASA/micasad/lss/CASACrypto.cs
index 6130fc45..58629acc 100644
--- a/CASA/micasad/lss/CASACrypto.cs
+++ b/CASA/micasad/lss/CASACrypto.cs
@@ -38,6 +38,7 @@ namespace sscs.crypto
 		private const int SALTSIZE = 64;
 		private const int ITERATION_COUNT = 1000;
 		private const int HASH_SIZE = 32;
+		private const uint MAX_FILE_SIZE = 16 * 1024 * 1024; //16 MB
 
 		internal static byte[] Generate16ByteKeyFromString(string sTheString, string sFilepath, bool bUseOldMethod)
 		{
@@ -179,7 +180,7 @@ namespace sscs.crypto
 			try
 			{                
 				//Get an decryptor.
-				RijndaelManaged myRijndael = new RijndaelManaged();
+				RijndaelManaged myRijndael = new RijndaelManaged();
                 ICryptoTransform decryptor = myRijndael.CreateDecryptor(key, baIV);             				
 				csDecrypt = new CryptoStream(ms, decryptor, CryptoStreamMode.Read);
 
@@ -206,8 +207,8 @@ namespace sscs.crypto
 				//Get an encryptor.
 				RijndaelManaged myRijndael = new RijndaelManaged();				
 			
-                // create IV
-                myRijndael.GenerateIV();
+                // create IV
+                myRijndael.GenerateIV();
                 baIV = myRijndael.IV;
 
 				ICryptoTransform encryptor = myRijndael.CreateEncryptor(key, baIV);
@@ -286,6 +287,33 @@ namespace sscs.crypto
                 fsEncrypt.Close();
         }
 
+        internal static void ComputeHashAndWriteToFile(byte[] baPasscode, string fileName)
+        {
+
+            FileStream fsHash = null;
+	    byte[] hash = null;
+
+            try
+            {                
+		SHA256 shaM = new SHA256Managed();
+		hash = shaM.ComputeHash(baPasscode);
+
+		fsHash = new FileStream(fileName, FileMode.Create);
+		File.SetAttributes(fileName, FileAttributes.Hidden);
+
+		fsHash.Write(hash, 0, hash.Length);
+		fsHash.Flush();
+            }
+            catch(Exception e)
+            {
+                CSSSLogger.ExpLog(e.ToString());
+                CSSSLogger.DbgLog("Computing hash and storing it in the file failed.");
+            }
+
+            if( fsHash != null )
+                fsHash.Close();
+        }
+
         internal static byte[] ReadFileAndDecryptData(byte[] key, 
             string fileName)
         {
@@ -326,6 +354,14 @@ namespace sscs.crypto
 					return null;
 				}
 
+                                if(fsDecrypt.Length  > MAX_FILE_SIZE )
+                                {
+					CSSSLogger.DbgLog("Size of the secret file exceeded the maximum allowed.");
+                                        csDecrypt.Close();
+                                        fsDecrypt.Close();
+                                        return null;
+                                }
+
 				ulong fileLen = (ulong)(fsDecrypt.Length - HASH_SIZE);
 				byte[] fromEncrypt = new byte[fileLen];
 
@@ -710,11 +746,8 @@ namespace sscs.crypto
                 EncryptAndStoreMasterPasscodeUsingString(baPasscode,
                     desktopPasswd,
                     fileName);                                              
-                EncryptDataAndWriteToFile(
-                    Encoding.Default.GetBytes(
-                    ConstStrings.MICASA_VALIDATION_STRING),
-                    baPasscode,
-                    validationFile);
+
+		ComputeHashAndWriteToFile(baPasscode, validationFile + "Hash"); //Hash of MPC is written to ".miCASAValidateHash" file
                 return baPasscode;         
             }
             catch(Exception e)
@@ -747,10 +780,8 @@ namespace sscs.crypto
                 fs.Flush();
                 fs.Close();
 
-                EncryptDataAndWriteToFile(
-                    Encoding.Default.GetBytes(ConstStrings.MICASA_VALIDATION_STRING),
-                    baPasscode,
-                    validationFile);
+                ComputeHashAndWriteToFile(baPasscode, validationFile + "Hash"); //Hash of MPC is written to ".miCASASrvValidateHash" file
+
             }
             catch(Exception e)
             {
@@ -761,6 +792,52 @@ namespace sscs.crypto
             return baPasscode;
         }
 
+	public static bool CompareHashes(byte[] baPasscode, string fileName)
+	{
+	    FileStream fsHash = null;
+	    try
+	    {
+#if LINUX
+                UnixFileInfo fsTest = new UnixFileInfo (fileName);
+                if((fsTest == null) || !(fsTest.Exists) || fsTest.IsSymbolicLink)
+#else
+                if (!File.Exists(fileName))
+#endif
+                {
+                    return false;
+                }
+
+		fsHash = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
+		byte[] storedHash = new byte[HASH_SIZE];
+		fsHash.Read(storedHash,0,storedHash.Length);
+
+		SHA256 sha = new SHA256Managed();
+		byte[] newHash = sha.ComputeHash(baPasscode);
+
+		for( int i = 0 ; i < HASH_SIZE; i++ )
+		{
+		    if(storedHash[i] != newHash[i])
+		    {
+			CSSSLogger.DbgLog("Comparision of hashes failed.");
+			fsHash.Close();
+			return false;
+		    }
+		}
+
+		fsHash.Close();
+		return true;
+	    }
+            catch(Exception e)
+            {
+                CSSSLogger.ExpLog(e.ToString());
+                CSSSLogger.DbgLog("Comparision of hashes failed.");
+            }
+
+	    if (fsHash != null)
+		fsHash.Close();
+	    return false;
+	}
+
         public static bool ValidatePasscode(byte[] baPasscode, string fileName)
         {
             /* Here we decrpyt a well known string, throw exception 
@@ -775,19 +852,28 @@ namespace sscs.crypto
 
             try
             {                
-                byte[] baString = ReadFileAndDecryptData(baPasscode, fileName);
-                string sString = Encoding.Default.GetString(baString);
-                char[] trimChars = {'\0'};
-                sString = sString.TrimEnd(trimChars);
-                if( ConstStrings.MICASA_VALIDATION_STRING.Equals(sString))
-                {
-                    CSSSLogger.DbgLog("Passed");
-                    return true;
-                }
-                else
-                {
-                    CSSSLogger.DbgLog("Failed");
-                    return false;
+		if(CompareHashes(baPasscode, fileName + "Hash"))
+		{
+		    CSSSLogger.DbgLog("Using the hash of MPC for validating the MPC");
+		    return true;
+		}
+		else
+		{
+		    CSSSLogger.DbgLog("Using the validation string encrypted with MPC for validating the MPC");
+		    byte[] baString = ReadFileAndDecryptData(baPasscode, fileName);
+		    string sString = Encoding.Default.GetString(baString);
+		    char[] trimChars = {'\0'};
+		    sString = sString.TrimEnd(trimChars);
+		    if( ConstStrings.MICASA_VALIDATION_STRING.Equals(sString))
+		    {
+			CSSSLogger.DbgLog("Passed");
+			return true;
+		    }
+		    else
+		    {
+			CSSSLogger.DbgLog("Failed");
+			return false;
+		    }
                 }
             }
             catch(Exception e)