在小的非二进制集合上构建一种安全的分组加密方案(英文)

We design a practical and provablysecure block ciper over small domain and non-binary inputs,which is also can be considered as a pseudorandom permutation on N elements.Our work is based on a relation we found between the small domain ciper and the negative hypergeometric probability(NHG) distribution.We prove that our block ciper achieves ideal security,that is,it is indistinguishable from a random permutation even if the adversary had already observed N plaintext-cipertext pairs.In particular,we initiate an efficient and sufficiently precise sampling algorithm for negative hypergeometric distribution.     

对2个基于身份签名方案的伪造攻击

对李—姜(2009)和谷—贾—姜(2011)依据Paterson方案(2006)分别提出的标准模型下基于身份的签名方案构造了3个有效的伪造攻击算法:攻击者在不得到任何签名用户私钥的情况下,仅通过选取随机参数以及多项式时间内的计算,便能够以显著的概率成功伪造任意用户对任意消息的有效签名。这些攻击算法显示李—姜和谷—贾—姜的基于身份签名方案都是不安全的。最后分析了方案遭受攻击的原因,并给出了2个可能的改进措施。     

多次电渗展开在平面电色谱中的应用探索

尝试建立一种新的平面电色谱展开方式多次电渗展开。其特征是：在第一次电渗展开结束后,重新湿润薄层板的干燥部位,再通电展开。这种操作可以重复多次直到斑点分离完全。反复探索发现：采用省略封尾步骤的反相C-18烧结板可以革除流动相中的缓冲盐,使多次电渗展开成为可能