-----BEGIN PGP SIGNED MESSAGE----- Sten Drescher writes:
Since I think that increasing the RSA keysize is supposed to double the attack time, if a RSA key size of N takes as much time to break as 1 IDEA key, making the RSA key N+8 bits makes it better to break the IDEA keys of 200 messages rather than the RSA key.
Does anyone know if there are comparisons of estimates of the time to break the IDEA session keys used in PGP vs time to break RSA keys of various sizes?
Off the top of my head, the figure I have usually heard quoted puts RSA at about 100 times slower than your average symmetric key algorithm. So ignoring key setup, I would expect an extra factor of 100 in the brute forcing time for RSA over IDEA. I don't believe it's worth spending much time worrying about your RSA key size. If you pick some decent size (1-2k), it's likely that RSA itself will have been broken, or your key compromised by some other means, before any direct brute force attack will succeed. Futplex <futplex@pseudonym.com> -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQEVAwUBMOsKNCnaAKQPVHDZAQHIRgf/ZS29BnGaZ60PeMlhIoniETAtI2VYNstM yFV6tl5w1Kzu9Q2TcJk/tdpW9QVbWOrB2IMdELBrk1urcYBS6YUBXcAlI7UhinA9 sapoZpz3WUCnRdb/64HkGFsOYgEVyVjsrrmu+M2RUUNRnOwWSS0KFAz8GYqj83ry xSpvrRNJPqCNARBsh9VPKgrRS1qNH5Zc1Tyu5Dr/E3OiQkzVCqHhQYYDj/PCESLL Y1Sly6n133Jq8J3TWoXAzeNKAOwy4tLz6TFn63OgbfcnTp1hndsMlIwCN3tzn9el T7b4LBMeVq2hXVkmotE0BURW7Phuckpmk1Xiow3vBXFMRxWPFz6lOg== =Njig -----END PGP SIGNATURE-----