re clipper chip technical details djb silverton berkeley edu d j bernstein writes summary elided the system as described here can t possibly work what happens when someone plugs the above ciphertext into a receiving chip to get m the receiving chip needs k p to get k p the receiving chip needs u c the only information it can work with is c if u c can be computed from c then the system is cryptographically useless and the key escrow is bullshit otherwise how is a message decrypted the description of the chip s operation evidently leaves out some of the key management aspects either the k p is the secret key corresponding to a public key which is broadcast at message initiation or it is the result of a diffie hellman key exchange or something similar either way there must be some protocols beyond those described here it isn t clear whether they are implemented in the clipper wiretap chip or must be provided by other system components hal finney
