On Mon, 17 Jul 1995, Andrew Roos wrote:

If the objective is to keep what Alice and Bob say SECRET then we have a problem if the entropy per bit of Alice's data plus the entropy per bit of Bob's data is less than one bit, because then there is only one likely decryption of the "ciphertext", which will reveal what both Alice and Bob are saying.

Yes, but presumably it's expected that they would be using secure encryption on the messages that they're sending. That might still provide some information about the message for traffic analysis, e.g. if you send a PGP message you have your key-id at the beginning, and if you knew the keys of all members of the DC-net you could XOR them and see who's talking to who. I'd have thought the most significant problem would be reserving the blocks in an anonymous fashion while not allowing denial-of-service attacks. Mark