Jintai Ding Christopher Wolf Bo-Yin Yang <i>l</i>-Invertible Cycles for <i>M</i>ultivariate <i>Q</i>uadratic (<i>MQ</i>) Public Key Cryptography. 266-281 2007 conf/pkc/2007 Public Key Cryptography http://dx.doi.org/10.1007/978-3-540-71677-8_18 db/conf/pkc/pkc2007.html#DingWY07