An anonymous reader writes "If you grab all the public keys you can find on the net, then you might expect to uncover a few duds — but would you believe that 2 out of every 1000 RSA keys is bad? This is one of the interesting findings in the paper 'Ron was wrong, Whit is right' by Lenstra, Hughes, Augier, Bos, Kleinjung and Wachter. Quoting from the paper's abstract: 'We performed a sanity check of public keys collected on the web. Our main goal was to test the validity of the assumption that different random choices are made each time keys are generated. We found that the vast majority of public keys work as intended. A more disconcerting finding is that two out of every one thousand RSA moduli that we collected offer no security. Our conclusion is that the validity of the assumption is questionable and that generating keys in the real world for "multiple-secrets" cryptosystems such as RSA is significantly riskier than for "single-secret" ones such as ElGamal or (EC)DSA which are based on Diffie-Hellman.'" For a layman's interpretation of the research, the NY Times has an article about the paper. Update: 02/15 01:34 GMT by S : Security researcher Dan Kaminsky has commented on the paper, saying that while the survey work itself is good, it doesn't necessarily support the paper's thesis. He writes, "On the most basic level, risk in cryptography is utterly dominated, not by cipher selection, but by key management. The study found 12,720 public keys. It also found approximately 2.94 million expired certificates. And while the study didn’t discuss the number of certificates that had no reason to be trusted in the first place (being self signed), it did find 5.4M PGP keys. It does not matter the strength of your public key if nobody knows to demand it."