At 10:08 AM 8/12/95, Sauroth wrote:

Actually quite a few hackers/phreaks have been encrypting phone conversations for a while. Not by any complex mathematics but simple modifications to the phone frequencies...Don't have any sites handy but for those interested I'll look up some of my old material. I'll also check a large compendium of boxes to see if Purple has been designated. Anyone interested in box plans of different colors e-mail me.

And the "simple modifications to the phone frequencies" points to why such things are not "strong crypto." At best, security through obscurity. At worst, self delusion. It gets back to the threat model. If the threat model is interception by the neighborhood kids, then schemes for frequency-hopping, scrambling, "warbling," and PhasorPhone-like diddling are OK. If the threat model is the local police department tapping one's phone, probably not enough, as they likely can gain access to the E-Systems DigiTrac 6700 and trivially unscramble the signal. Long term, only robust, strong crypto works (Michael Handler's "civil liberties through complex mathematics"). --Tim May ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@got.net (Got net?) | anonymous networks, digital pseudonyms, zero 408-728-0152 | knowledge, reputations, information markets, Corralitos, CA | black markets, collapse of governments. Higher Power: 2^756839 | Public Key: PGP and MailSafe available. "National borders are just speed bumps on the information superhighway."