In message <3C93EEA3.28833ABD@greendragon.com>, William Allen Simpson writes: >"The Purple Streak (Hilarie Orman)" wrote: >> Mild-mannered S. Kent is in reality SuperNoSecMan. He adds >> the essential anti-replay counter to IPsec protocols and, ... >> causes people to NOT adopt them? > >Actually, of course, Steve Kent did not add the counter. It was in >swIPe, from the beginning. It was in my drafts, from the beginning. > >It was certain members of the WG who insisted we didn't need the >counter. At least one has admitted he was wrong. Are you ever going to >admit you were? > >Anyway, when we published the first set of RFCs, I carefully documented >the need for a Replay Protection sequence number in 1995: > "Internet Security Transform Enhancements" > Right. The only copy I could find was from 1996, but I don't think that that difference is important. (http://www.watersprings.org/pub/id/draft-simpson-ipsec-enhancement-00.txt) The problem with it -- and the reason I had objected to sequence numbers -- is that it never justified *why* they were necessary, beyond rather minor DoS prevention. It simply said "replay protection provides cryptographically secure at-most-once datagram delivery." But there was no analysis of why one would want that. The same is true of the swIPe paper and I-D -- there was no analysis beyond saying "replay protection". When attacks on confidentiality were developed that exploited the lack of replay prevention, I changed my mind and strongly supported sequence numbers. The difference is that there was then a reason. For what it's worth, Kent applauded the restoration of the counter -- he knew it was necessary. But Bill, I'm trying to understand what your point is. We can't force people to use security. IPsec is standard in most major business operating systems (Win2K, Solaris, *BSD, etc.) and available for for Linux. There are hardware solutions -- I have a small IPsec box with me in Minneapolis. But except for VPN scenarios, most people choose not to use it. I think there's a lesson there, but I fail to see how Steve Kent or any of the other players in the history of IPsec are at all at fault. --Steve Bellovin, http://www.research.att.com/~smb Full text of "Firewalls" book now at http://www.wilyhacker.com