A Mighty Number Falls
space_in_your_face writes "An international team has broken a long-standing record in an impressive feat of calculation. On March 6, computer clusters from three institutions (the EPFL, the University of Bonn, and NTT in Japan) reached the end of eleven months of strenuous calculation, churning out the prime factors of a well-known, hard-to-factor number — 2^1039 - 1 — that is 307 digits long." The lead researcher believes "the writing is on the wall" for 1024-bit encryption. "Last time, it took nine years for us to generalize from a special to a non-special hard-to factor number (155 digits). I won't make predictions, but let's just say it might be a good idea to stay tuned."
This is incorrect.
1 5017753575689937658432079465\1 4451080388584562460719428810\9 2146903328852155899782370013\3 4387684495620912657652829388\
The two factors are prime, and multiply to the given number, but that number is not 2^1039-1.
2^1039-1=
5890680864316836766447387249177476247119386964598
5559932591384900650140340063891615625817543763223
7610698331745992221533871131893632012106238622173
7184806201826907368669534112523820726591354912103
7
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
So...f ffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffff fffffffffffe :)
0x7ffffffffffffffffffffffffffffffffffffffffffffff
is prime...
Interesting
Who's first to write it as decimal here?
Who's to beat the lameness filter while writing it in binary?
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2