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Ahmed Chalabi and Iran’s encryption

Security: some crypto drama.

Ahmad Chalabi apparently told the Iranian government that the NSA had broken their secret code, according to ‘US intelligence officials’: NYTimes: Chalabi Reportedly Told Iran That U.S. Had Code. This story is still running — Bruce Schneier has just posted his expert opinion, as has Ross Anderson. As I noted on Eric Rescorla’s weblog, here’s my (non-expert) theory ;)

It’s known that the Iranians used Crypto AG equipment up until about 1992, and it’s been widely reported that Crypto AG’s systems were backdoored by the NSA and traffic routinely decrypted. (also, Baltimore Sun story, 1995)

Reportedly, the Anglo-Irish discussions of the 1985 were a rather one-sided affair, because the Irish government used Crypto AG machines to communicate between their Embassy in London and Dublin, and intercepts of their reports were fed back to the UK government.

In addition, according to this article (backup), the NSA also provided Iraq with intercepts of Iranian secret traffic, while Iraq was a US ally — which could explain why Chalabi would have known about it.

It also speculates as to how it was done:

‘Knowledgeable sources indicate that the Crypto AG enciphering process, developed in cooperation with the NSA and the German company Siemans, involved secretly embedding the decryption key in the cipher text. Those who knew where to look could monitor the encrypted communication, then extract the decryption key that was also part of the transmission, and recover the plain text message. Decryption of a message by a knowledgeable third party was not any more difficult than it was for the intended receiver. (More than one method was used. Sometimes the algorithm was simply deficient, with built-in exploitable weaknesses.)’

So my opinion is that Chalabi’s claim was very old news from the 80’s and early 90’s — which pretty much fits in with the rest of his tip-offs to everyone else ;)

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