Hiroki Ueda

Sieving using bucket sort

This paper proposes a new sieving algorithm that employs a bucket sort as a part of a factoring algorithm such as the number field sieve. The sieving step requires an enormous number of memory updates; however, these updates usually cause cache hit misses. The proposed algorithm dramatically reduces the number of cache hit misses when the size of the sieving region is roughly less than the square of the cache size, and the memory updates are several times faster than the straightforward implementation.

Experiments on the linear algebra step in the number field sieve

This paper shows experimental results of the linear algebra step in the number field sieve on parallel environment with implementation techniques. We developed an efficient algorithm that shares the sum of vectors in each node, and the network structure among the nodes only requires to include a ring. We also investigated the construction of a network for the linear algebra step. The construction can be realized through switches and network interface cards, whose prices are not expensive. Moreover, we investigated the implementation of the linear algebra step using various parameters. The implementation described in this paper was used for the integer factoring of a 176 digit number by GNFS and a 274 digit number by SNFS.