Dodson, B.Lenstra, Arjen K.Leyland, P.Lioen, W.Montgomery, P. L.Murphy, B.Riele, H. T.Zimmermann, P.Cavallar, S.2011-03-292011-03-292011-03-29199910.1007/b72231https://infoscience.epfl.ch/handle/20.500.14299/65731On February 2, 1999, we completed the factorization of the 140-digit number RSA-140 with the help of the Number Field Sieve factoring method (NFS). This is a new general factoring record. The previous record was established on April 10, 1996 by the factorization of the 130-digit number RSA-130, also with the help of NFS. The amount of computing time spent on RSA-140 was roughly twice that needed for RSA-130, about half of what could be expected from a straightforward extrapolation of the computing time spent on factoring RSA-130. The speed-up can be attributed to a new polynomial selection method for NFS which will be sketched in this paper.Large Primestext::conference output::conference proceedings::conference paper