## Cryptology ePrint Archive: Report 2019/949

A Note on Parameter Choices of Round5

Yongha Son

Abstract: We examine the current parameter choice of Round5, and rectify its consideration of the improved dual attack due to Albrecht [Albrecht-EC17]: there is one significant optimization of Albrecht's dual attack, which was not reflected to Round5 parameter choices. By taking this into consideration, some parameter choices of Round5 cannot enjoy the claimed security level.

Category / Keywords: public-key cryptography / Public-Key Cryptography, Learning With Errors