Section: New Results

Number Field Sieve

Participants : Emmanuel Thomé, Paul Zimmermann [contact] .

Together with Shi Bai (Australian National University), E. Thomé and P. Zimmermann used Cado-nfs to factor RSA-704, a 212-digit number, to check scalability of the software on large factorizations [10] . This is the second largest number factored by any GNFS software so far, and the largest one factored by Cado-nfs . This experiment was very helpful, since it demonstrated several weaknesses of the code, that have been addressed since then.

Together with Shi Bai (Australian National University), P. Zimmermann wrote a preprint describing the algorithm used in Cado-nfs for the size-optimization of sextic polynomials [11] .

Alain Filbois, Shi Bai (Australian National University) and P. Zimmermann improved the polynomial selection code. With parameters used to find good polynomials for RSA-896, a total speedup by a factor 14 was obtained, with both algorithmic and implementation improvements.