RSA Laboratories

RSA-576 is factored!

On December 3, 2003, a team of researchers in Germany and several other countries reported a successful factorization of the challenge number RSA-576. According to the announcement by J. Franke:

The factors [verified by RSA Laboratories] are:




Lattice sieving was done by J. Franke and T. Kleinjung using Hardware of the Scientific Computing Institute and the Pure Mathematics
Institute at Bonn University, of the Max Planck Institute for Mathematics in Bonn, and of the Experimental Mathematics Institute in Essen.

Line sieving was done by P. Montgomery and H. te Riele at the CWI, by F. Bahr and his family, and by NFSNET (which at that time consisted of D. Leclair, Paul Leyland [ working for Microsoft Res. Ltd ] and R. Wackerbarth).

Postprocessing was supported by the BSI.

RSA-576, a 576-bit or 174-digit number, is the first of the RSA challenge numbers to be factored from the "new" challenge started in 2001. The largest previously factored challenge number is RSA-160 from the "old" challenge, where numbers were designated by their length in decimal digits rather than bits; RSA-160 is 530-bit number.