Friday, 8 January 2010

RSA 768 has bitten the dust

I see that RSA 768 has bitten the dust. What is interesting is the relationship to bits and compromise of the algorithm.

See http://eprint.iacr.org/2010/006.pdf  for the paper and how it was done.

The previous record NFS factorization with respect to RSA a 663-bit RSA-200 key on May 9, 2005.

Based on the factorisation rates from the 512 bit key, this makes a 1.7 bit per month result (+/- 0.12). This is not similar to the growth of computational power at 1.039 per month (or a 2.0 factor each 18 months).

1024 bit keys have not been factored as yet, but an estimate based on the results in factoring RSA from 2001 to the present, one could expect (if the current extrapolation holds) that 1024 bit RSA keys will be factored between August and Sept 2021 (+/- 5 months).

However, based on a number of details of the sieving process, if I had to put money on this, I would place my bet at Jan 2018.

No comments: