private static string GetHashValueMd5Checksum(byte[] input)
{
// Validate MD5 Value
var md5Check = MD5.Create();
md5Check.TransformBlock(input, 0, input.Length, null, 0);
md5Check.TransformFinalBlock(new byte[0], 0, 0);
// Get Hash Value
byte[] hashBytes = md5Check.Hash;
string hashVal = Convert.ToBase64String(hashBytes);
return hashVal;
}