This Yagisawa paper is of poor quality and lacks adequate proofs. It unfortunately uses the exact title as a 2011 paper by Brakerski, Gentry, and Vaikuntanathan

This Yagisawa paper is of poor quality and lacks adequate proofs. It unfortunately uses the exact title as a 2011 paper by Brakerski, Gentry, and Vaikuntanathan: https://eprint.iacr.org/2011/277.pdf https://eprint.iacr.org/2011/277.pdf The BGV paper is the real deal.