re how to detect use of an illegal cipher in article apr clarinet com brad clarinet com brad templeton writes your honour the suspect suddenly started using another level of cryptography and we can t tap his phone calls any more he must have something to hide please sign the warrant to search his house what they would need to do though is make sure that nobody has access to decent crypto in the first place they probably can t tell clippered voice from clippered triple desed voice until they get their copy of your key any criminal who s going to use encryption will do it under cover of clipper the only way to avoid this will be to try to prohibit strong encryption i probably shouldn t say this but they could try to detect the use of an illegal cypher by transmitting in the clear some statistical properties of the plaintext an old fashioned wiretap could then detect the use of pre encryption which would drastically increase the measured entropy of the input a countermeasure to this would be to use steganographic techniques which put out voice you can tell if the nsa built this feature in blow on the mike and observe whether a band of thugs comes through your ceiling pgp key by finger or e mail eli ebrandt jarthur claremont edu
