Yoshinori Aono Manindra Agrawal Takakazu Satoh Osamu Watanabe On the Optimality of Lattices for the Coppersmith Technique. 108 2012 2012 IACR Cryptology ePrint Archive http://eprint.iacr.org/2012/108 db/journals/iacr/iacr2012.html#AonoASW12 informal publication