Zero round trip secure communications is implemented based on two noisy secrets. A sender system: calculates a required number of sub-keys to have at least one noiseless sub-key; for each first negotiated secret sub-key, uses the sub-key to encrypt a first half of a message key and test bytes, and adds the encrypted first half of the message key and the encrypted test bytes to the encrypted message; for each second negotiated secret sub-key, uses the sub-key to encrypt a second half of the message key and the test bytes, and adds the encrypted second half of the message key and the encrypted test bytes to the encrypted message; and sends the encrypted message, message MAC information, encrypted first halves of the message key with associated encrypted test bytes, and encrypted second halves of the message key with associated encrypted test bytes to a receiver.