Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!usc!wuarchive!udel!haven!decuac!bacchus.pa.dec.com!hollie.rdg.dec.com!jch From: jch@dyfed.rdg.dec.com (John Haxby) Newsgroups: mail.uk-sendmail-workers,comp.mail.sendmail Subject: Re: Forging messages Message-ID: <1990Nov7.160856.6365@hollie.rdg.dec.com> Date: 7 Nov 90 16:08:56 GMT References: <25249.9011061356@expya.cs.exeter.ac.uk> <1990Nov6.234722.8580@mp.cs.niu.edu> Sender: news@hollie.rdg.dec.com (USENET News System) Reply-To: jch@dyfed.rdg.dec.com (John Haxby) Organization: Digital Equipment Corporation Lines: 20 Proof against forging is somewhat difficult with sendmail -- the best way is to use encryption, preferably double public key encryption (you know, the thing whereby you encrypt with your own private key and then the intended recipients public key and the recipient uses your public key and his private key to decrypt the message). X.400 '88 has the infra-structure to support secure mail and digital signatures, proof of posting and all that junk. The only snag with all of this is that it relies rather heavily on public key or private key encryption and both forms can be cracked open with sufficient mips -- people have be factoring products of large primes for a while now, cracking DES passwords is easy by comparison. -- ------- John Haxby, Definitively Wrong. Digital Reading, England <...!ukc!wessex!jch>