.@mcpherrinm factored the RSA keys of a Certificate Authority...
… from the 90s.
(Don't worry, they are wee 512-bit keys that have been factorable for decades.)
looks like ordian from parity just pwned both SHA-256 and RSA challenges, finding the most optimized circuits for both!
EDIT: nevermind, as I wrote this @sleepdefic1t wrote a better RSA circuit! How long will he stay up there?