The first enormous distributed factorisation was RSA-129, a 129-digit 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 through the internet, and the final stages of the calculation performed on a MasPar supercomputer at Bell Labs.
Between January and August 1999, RSA-155, a 155-digit challenge number prepared by the RSA company, was factorised using GNFS with relations again contributed by a large group, and the final stages of the calculation performed in just over nine days on the Cray C916 supercomputer at the SARA Amsterdam Academic Computer Center.
In April 2003, the same team factored the 160-digit RSA-160 using about a hundred CPUs at BSI, with the final stages of the calculation done using 25 processors of an SGI Origin supercomputer.
On December 12, 2009, a team including researchers from the CWI, the EPFL, INRIA and NTT in addition to the authors of the previous record factored RSA-768, a 232-digit semiprime.
Sieving was done at the CWI, at the Scientific Computing Institute and the Pure Mathematics Department at Bonn University, and using private resources.
As of the end of 2007, thanks to the constant decline in memory prices, the ready availability of multi-core 64-bit computers, and the availability of the efficient sieving code via ggnfs[18] and of robust open-source software such as msieve[19] for the finishing stages, special-form numbers of up to 750 bits (226 digits) and general-form numbers of up to about 520 bits (157 digits) can be factored in a few months on a few PCs by a single person without any special mathematical experience.
In September 2013, the 696-bit (210-digit) RSA-210 was factored[23] using institutional resources; between March 2013 and October 2014, another 210-digit number (the 117th term in the home prime sequence starting with 49),[24] using $7600 worth of processing time on Amazon EC2 machines[25] for the sieving, and four months on a dual Xeon E5-2687W v1 for the linear algebra.