Paradigms for Paranoids

Off-the-record messaging

By Jorn Barger • Get more from this author

Posted in Developer, 14th February 2005 22:15 GMT

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Codecon 2005 The fourth annual CodeCon - "a workshop for developers of real-world applications that support individual liberties" - convened Friday afternoon (11 Feb) at Club NV (envy, not Nevada), amid ghostly laptop panels hovering in violet-tinted danceclub murk.

First-day registrations reached a respectable 90 (at $80 each), with more expected as the weekend progresses.

The highlight among the first day's five presentations was Ian Goldberg and Nikita Borisov on Off-the-Record Messaging (OTR), where 'messaging' can be instant messaging in any of its various formats, including online games, and "off the record" is meant to emulate as closely as possible the realworld strategy of sneaking off somewhere private, where you can talk with absolutely no record of what you said that might come back later to haunt you. (I was reminded of Maxwell Smart's ill-omened Cone of Silence.)

Conventional crypto technologies are optimised for (e.g.) enduring longterm contracts, but OTR prefers that messages be written as if in sand, via "perfect forward secrecy" (PFS) and "repudiable authentication". (Even if your conversation is cracked and transcribed, the programmers have included a "forgery toolkit" that allows you to repudiate such transcripts as trivial to forge.)

With such glorious levels of intimate distrust, I was surprised Ian didn't name his exemplary chatterers "Bill" and "Monica" - both Ian and Nikita were witty presenters, with the former doing funny voices, and the latter offering, when a projector bulb blew during their demo, to substitute an interpretive dance.

Another maniacally brilliant twist is that they can invisibly solicit OTR dialogs from strangers in chat by appending an inconspicuous all-whitespace flag, consisting of a characteristic arrangement of 24 spaces and tabs. And it was a pleasure, as well, to hear the consistently high level of followup questions after their talk.

Other first-day presentations: Hal Finney on digital cash ("The owner of the server is the enemy"), David Reid and Ben Laurie of Apache on adding group-based access controls to the certification process, Walter Landry's exhaustive comparative benchmarking of distributed version-control apps (due to be posted here), and Cat Okita on reputation management.

See the schedule and program for details. ®

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