Cryptanalysis of the Quadratic Zero-Testing of GGH.

In this short note, we analyze the security of the quadratic zero-testing procedure for the GGH13 graded encoding scheme, which was recently proposed by Gentry, Halevi and Lepoint. We show that this modification fails to immunize the GGH13 construction against zeroizing attacks, and that the modified scheme is susceptible to the same attacks as the original one.