Only accepting e-mail from known parties

[Jeff Hupp]

On 25 Dec 95 at 7:45, Dr. Dimitri Vulis wrote:

[much on a pgp based gateway filter for email]
: 
: This is much better than nothing. This would stop the e-mail being
: sent to everyone who's ever posted to Usenet. I see a couple of attacks:
: 
: 1. Alice only accepts signed e-mail from Bob. Carol receives a signed e-mail
: from Bob to Carol, sends 10,000 e-mails to Alice (via sendmail) with From: bob,
: same body+signature, possibly varying message-ids and subjects.
: 
: 2. Alice only accepts signed e-mail from Bob. Carol, a rogue sysadmin,
: intercepts an e-mail from Bob to Alice, sends 10,000 more copies of it to Alice
: (via sendmail) with From: bob, possibly varying message-ids and subjects.
: 
: As I keep pointing out, pgp-signing the body is not enough.
: 

	Keep checksums of signitures (or body text) for a week, duplicate 
messages are routed to /dev/null.

-- 
JHupp at gensys.com           |For PGP Public Key:
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