RSA-640 Factored By Eric W. Weisstein November 8, 2005--A team at the German Federal Agency for Information Technology Security (BSI) recently announced the factorization of the 193-digit number 310 7418240490 0437213507 5003588856 7930037346 0228427275 4572016194 8823206440 5180815045 5634682967 1723286782 4379162728 3803341547 1073108501 9195485290 0733772482 2783525742 3864540146 9173660247 7652346609 known as RSA-640. The team responsible for this factorization is the same one that previously factored the 174-digit number known as RSA-576 (MathWorld headline news, December 5, 2003) and the 200-digit number known as RSA-200 (MathWorld headline news, May 10, 2005). RSA numbers are composite numbers having exactly two prime factors (i.e.,...