Zhifang Zhang Mulan Liu Yeow Meng Chee San Ling Huaxiong Wang Strongly Multiplicative and 3-Multiplicative Linear Secret Sharing Schemes http://arxiv.org/abs/0812.2518 2008 CoRR abs/0812.2518 db/journals/corr/corr0812.html#abs-0812-2518 informal publication