An international team of mathematicians and computer scientists including two CWI researchers has found the two prime factors of a specially prepared encryption testing number called RSA-576, a number of 576 bits or 174 digits. This was announced on December 3, 2003 by team leader Jens Franke from Bonn University. Factoring the number is equivalent to cracking a key of 576 bits in the widely used RSA crypto system. The security of this crypto system is based on the assumption that such large numbers are hard to factor. By using advanced methods and a large number of computers and workstations, the group managed to obtain the factors in about one year. Herman te Riele and Peter Lawrence Montgomery from CWI's computational number theory and data security group MAS 2.2 contributed to the operation. It is not the first time te Riele is involved in a world factoring record. In 1999 he led a group that managed to break an RSA key of 512 bits or 155 digits. This is representative for keys used in those days for securing internet traffic.
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