RSA-640 has 193 decimal digits (640 bits). A cash prize of US$20,000 was offered by RSA Security for a successful factorization. On November 2, 2005, F. Bahr, M. Boehm, J. Franke and T. Kleinjung of the German Federal Office for Information Security announced that they had factorized the number using GNFS as follows:
The computation took five months on 80 2.2 GHz AMD Opteron CPUs.
The slightly larger RSA-200 was factored in May 2005 by the same team.
2.
RSA-200
RSA-200 has 200 decimal digits (663 bits), and factors into the two 100-digit primes given below.
On May 9, 2005, F. Bahr, M. Boehm, J. Franke, and T. Kleinjung announced[28][29] that they had factorized the number using GNFS as follows:
The CPU time spent on finding these factors by a collection of parallel computers amounted – very approximately – to the equivalent of 75 years work for a single 2.2 GHz Opteron-based computer.
