Integer factorization records

== Numbers of a general form

The first very large distributed factorisation was RSA129, a challenge number described in the Scientific American article of 1977 which first popularised the RSA cryptosystem. It was factorised between September 1993 and April 1994, using MPQS, with relations contributed by about 600 people from all over the Internet,

Between January and August 1999, RSA155, a challenge number prepared by the RSA company, was factorised using GNFS with relations again contributed by a large group.

A 176-digit cofactor of 11^281+1 was factored by Aoki, Kida, Shimoyama and Ueda Template:Cite web url between February and May 2005 using machines at NTT and Rikkyo University in Japan.

The RSA200 challenge number Template:Cite web url was factored by Franke, Kleinjung et al between December 2003 and May 2005, using a cluster of 80 Opteron processors at BSI in Germany; the announcement was made on 9 May 2005.

== Numbers of a special form

6^353-1, of 911 bits, was factored Template:Cite web url by Aoki, Kida, Shimoyama and Ueda between September 2005 and January 2006 using SNFS.