Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site calmasd.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!sdcsvax!sdcc6!calmasd!jpm From: jpm@calmasd.UUCP (John McNally) Newsgroups: net.followup,net.flame,net.politics Subject: Re: Big Brother IS wtaching you - cross border phone traffic Message-ID: <213@calmasd.UUCP> Date: Tue, 11-Dec-84 12:34:24 EST Article-I.D.: calmasd.213 Posted: Tue Dec 11 12:34:24 1984 Date-Received: Thu, 13-Dec-84 01:49:33 EST References: <237@celerity.UUCP> <221@looking.UUCP>, <1832@sdcc6.UUCP> Organization: Calma Company, San Diego, CA Lines: 37 Xref: watmath net.followup:4214 net.flame:7193 net.politics:6273 >> I wonder what would happen if we stuck encryption on the trans-atlantic >> link? Would there be some curious counter-intelligence forces (their only >> descriptive name) poking around within minutes? >> Brad Templeton, Looking Glass Software Ltd. - Waterloo, Ontario 519/884-7473 >Only to see if the algorithm is neat. You forget NSA does the codes for >*everything* that the government wants to encrypt. >John Testa UCSD Chemistry sdcsvax!sdcc6!ix241 I think that Brad's idea is a good one. But, I think that John is misinformed. This is my understanding of things (not guaranteed correct): The government surely knows how to crack the DES (Data Encryption Standard) easily, which they (of course) encourage everyone to use because (so the argument goes) it has been shown to be secure. Here, secure means than any attacker will expend far more resources cracking the code than the value of any info obtained. I believe that DES uses a 51 bit code??? (the technical content of the following is certainly correct): However, using RSA public-key cryptography, I could encode a message that would give the NSA fits. RSA is based upon the intractability (to date) of the prime factoring problem. If I use an 800 bit key (the product of two large primes) a lot of computational power must be expended in finding the key's prime factors (admittedly, I would have to expend a bit of computing power encoding the message, but nowhere near what is required to crack it). There are just too many big primes and they are hard as hell to find. I do admit though that they will try and they will eventually succeed. Maybe Piet or some of those other mellow fellows in Amsterdam would like to give it a try. Given their political inclinations, they will certainly trigger the NSA attention. My only questions: Will we ever know anything about it and will anyone care when I disappear??? -- John McNally Calma 11080 Roselle St. San Diego CA 92121 ...{ucbvax,decvax}!sdcsvax!calmasd!jpm (619)-458-3230