public static Byte[] GetValueAsBytes(Int64 value) { String valueAsString = value.ToString("0"); Org.BouncyCastle.Math.BigInteger v = new Org.BouncyCastle.Math.BigInteger(valueAsString); Byte[] x = new Byte[8]; Byte[] y = v.ToByteArray(); Array.Reverse(y); Array.Copy(y, x, y.Length); string forDebug = v.ToHexNumberString(); return(x); }