Implementation on GPU of a provably secure lattice-based stream cipher

In this paper we construct a lattice-based stream cipher using the provable secure hardness of the Short Integer Solution (SIS) problem as security basis. We apply the standard approach of building a pseudo-random generator, which produces a sequence to be combined with the clear text. Moreover, as an alternative to gain efficiency both in terms of space and speed, we suggest the use ideal lattices in the cipher construction. Currently, there is no known attack that could exploit this choice. Finally, by employing a mild security notion, we are able to achieve a simple and efficient construction.

In the implementation corresponding to the source code added to this page, we have obtained. We used the optimizations proposed in the SWIFFT hash functions [15] in order to get efficient FFT operations. We reached a throughput of 27 Mbps with the stream cipher, on a Dual Core Pentium T2330 at 1.60 GHz, running Linux 2.6.32-24. The compiler used to generate the code was gcc, version 4.4.3-4. This throughput is approximately 30 times slower than AES in CTR mode, from the Crypto++ library, Version 5.6.1.

The parameters used (the same as SWIFFTX) assure a security level of 100 bits, and result in a computational effort of 540 cycles per byte produced.