中文摘要：

我们与类似的代数学的结构学习一些同构的秘密成员系统的安全。那些秘密成员系统有特殊共有的财产，这被发现。把性质基于这些，我们提出二骑车的攻击并且指出攻击是有效的一些在下面参数。随机选择的参数几乎不可能地提交到如此的攻击，这被验证。无论如何，二个有效方法被给为他们计算的超过 1 024 位被显示出对我们的骑车的攻击脆弱的某些同构的秘密成员系统，和二 moduli 构造弱参数。强壮的素数应该被用来避免弱参数，这被结束。

英文摘要：

We study security of some homomorphic cryptosysterns with similar algebraic structure. It is found out that those cryptosystems have special common properties. Based on these properties, we pose two cycling attacks and point out some parameters under which the attacks are efficient. It is verified that randomly selected parameters almost impossibly submit to such attacks. Anyhow, two effective methods are given to construct weak parameters for certain homomorphic cryptosystems, and two moduli over 1 024 bits computed by them are shown to be vulnerable to our cycling attacks. It is concluded that strong primes should be used to avert weak parameters.