Picnic improvements

[Greg Zaverucha]

Dear pqc-forum

The attached report describes some recent results that can be used to improve Picnic. We've worked out tentative parameters for the improved design, we call Picnic4, for security level L1. The highlight is a reduction in signature size. Picnic4 signatures can be 7987 bytes compared to 12595 for Picnic3 (the current version). Our implementation effort is ongoing, so we do not yet have a good comparison of the running time of signing and verification -- some preliminary benchmarks are in our write-up. A more complete version of the paper is underway.

 

Greg Zaverucha & Daniel Kales