ComputeHash

        public static string ComputeHash(string plainText, byte[] saltBytes)
        {
            // Convert plain text into a byte array.
            var plainTextBytes = Encoding.UTF8.GetBytes(plainText);

            // Allocate array, which will hold plain text and salt.
            var plainTextWithSaltBytes = new byte[plainTextBytes.Length + saltBytes.Length];

            // Copy plain text bytes into resulting array.
            for (var i = 0;i < plainTextBytes.Length;i++)
                plainTextWithSaltBytes[i] = plainTextBytes[i];

            // Append salt bytes to the resulting array.
            for (var i = 0;i < saltBytes.Length;i++)
                plainTextWithSaltBytes[plainTextBytes.Length + i] = saltBytes[i];

            // Use the SHA512 encryption
            var hash = new SHA512Managed();

            // Compute hash value of our plain text with appended salt.
            var hashBytes = hash.ComputeHash(plainTextWithSaltBytes);

            // Create array which will hold hash and original salt bytes.
            var hashWithSaltBytes = new byte[hashBytes.Length + saltBytes.Length];

            // Copy hash bytes into resulting array.
            for (var i = 0;i < hashBytes.Length;i++)
                hashWithSaltBytes[i] = hashBytes[i];

            // Append salt bytes to the result.
            for (var i = 0;i < saltBytes.Length;i++)
                hashWithSaltBytes[hashBytes.Length + i] = saltBytes[i];

            // Convert result into a base64-encoded string.
            var hashValue = Convert.ToBase64String(hashWithSaltBytes);

            return hashValue;
        }