The term horizontal surface is identified in base64 scheme by the sequence aG9yaXpvbnRhbCBzdXJmYWNl, while the MD5 signature is equal to 278e86e0d0afbc277d03100513c7d68c. The ASCII encoding of horizontal surface in hexadecimal notation is 686f72697a6f6e74616c2073757266616365.