Revisiting the Hybrid Attack on Sparse Secret LWE and Application to HE Parameters
Yongha Son, Jung Hee Cheon · 2019
In the practical use of the Learning With Error (LWE) based cryptosystems, it is quite common to choose the secret to be extremely small: one popular choice is ternary ((±1,0),coefficient vector, and some further use ternary vector having only small numbers of nonzero coefficient, what is called \em sparse and ternary vector. This use of small secret also benefits to attack algorithms against LWE, and currently LWE-based cryptosystems including homomorphic encryptions (HE) set parameters based on the attack complexity of those improved attacks.