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IP: Steganography & covert communications - Between Silk and Cyanide
From: David Farber <dave () farber net>
Date: Sun, 30 Dec 2001 18:22:56 -0500
To: cryptography () wasabisystems com, gnu () toad com Subject: Re: Steganography & covert communications - Between Silk and Cyanide Date: Sun, 30 Dec 2001 14:59:10 -0800 From: John Gilmore <gnu () toad com> > generally, imagine you are a consultant to some nefarious > organization and think about what it would take to convince them that > the method you propose is safe, capable of being taught to their > covert agents, and tolerant of the inevitable slip ups in the field > (and remember their attitude toward warrantee disclaimers). Along these lines I can't help but recommend reading one of the best crypto books of the last few years: Between Silk and Cyanide Leo Marks, 1999 This wonderful, funny, serious, and readable book was written by the chief cryptographer for the 'nefarious organization' in England which ran covert agents all over Europe during WW2 -- the Special Operations Executive. He found upon arriving (as a teenager) that agents were constantly dying in the field because of poor codes and poor encryption and radio transmission practices. Their bad systems had been penetrated for years, and in some countries such as the Netherlands, all of their agents had been killed or captured by the Germans. He shored up their poor systems until he could work around the bureacracy to get them replaced. He taught the receiving code clerks in England how to decode even garbled messages, rather than asking agents to re-send them. (Re-sends of the same text gave the enemy even more trivial ways to crack the codes.) He trained each outgoing agent in good coding practices, then watched heartbroken as many were captured. He independently reinvented one-time pads, and had them printed on silk. They could be sewn into the linings of clothing for non-detection even during searches by the enemy, and so that as each part was used, it could be cut off and burned to keep previous messages secret (providing forward secrecy). Leo Marks died almost a year ago, but fortunately he wrote down much of the practical knowledge that came from making and breaking codes for a covert organization working in a very hostile environment. Here is his AP obituary: http://surf.bookwire.com/news/authors/2001/01/22/wstm-/2440-1571-Britain-Obit-Marks..html John Gilmore --------------------------------------------------------------------- The Cryptography Mailing ListUnsubscribe by sending "unsubscribe cryptography" to majordomo () wasabisystems com
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- IP: Steganography & covert communications - Between Silk and Cyanide David Farber (Dec 30)