Back in August, I attended the CRYPTO 2006conference in Santa Barbara, where Daniel Bleichenbacher gave aneye-opening talk that highlighted a very common implementation mistakepeople make with the RSA cryptosystem. Since my own background is incryptography I thought I would try to describe not only this commonmistake and its implications, but also some details regarding why thismistake leads to vulnerabilities, in a way that’s hopefully suitablefor a wide audience. For those who don’t recognize the name, Daniel isa well-known and brilliant cryptographer who, among other things, foundcryptographic flaws in SSL v3.0 and also the random number generatorassociated with the Digital Signature Algorithm. Well, he is at itagain!
Before going any further I want to emphasize thatthe flaw Daniel found is not one that is inherent in the RSA algorithmitself; rather, it deals with a specific...
