An emailer named Stan found my RSA-640 entry from a few years back and asked a few questions about my assumptions. I hadn’t thought about the challenge in a while, so I was surprised when I found out the challenge number was factored last November. Validating my theory about the factors’ length, each was 97 digits.

The next-highest challenge number is RSA-704. I’ll publish a new lottery script for it, perhaps with some new tricks, soon.