The term keep one's mouth shut is identified in base64 scheme by the sequence a2VlcCBvbmUncyBtb3V0aCBzaHV0, while the MD5 signature is equal to 5e2d71b3e90962f8b98174cc928a5b28. The ASCII encoding of keep one's mouth shut in hexadecimal notation is 6b656570206f6e652773206d6f7574682073687574.