“MathWorld News is reporting that RSA-640 has been factored. F. Bahr, M. Boehm, J. Franke, and T. Kleinjung, memebers of the German Federal Agency for Information Technology Security (BSI) announced they had cracked the 193-digit number last Friday using the General Number Field Sieve. The team purportedly used 80 opteron CPUs and 5 months to achieve victory.”
I realise that 1024bit keys are exponentially bigger then 640bit, however this shows that the time to crack 1024bit keys are getting awfully close to useless when dealing with material that needs a longish life span, not to mention some of the root certificates in browsers are still 1024bit, and even if it took these guys 5 times as long, those certificates are still going to be valid when they get finished.
And people complained about the 4096bit certificate CAcert uses 🙂 (well complained because not all apps supported key sizes bigger then 1024bit!)
PS found this website, which gives a break down of how long you can expect varying keylengths to be good for.