BGG^(+)14属性基加密方案的模数分析

Modulus analysis of the BGG^(+)14 attribute-based encryption scheme

目的 分析BGG^(+)14属性基加密方案中模数的选取对其安全性的影响。方法 通过假定模数为合数及设定联合差错向量,利用BGG^(+)14属性基加密方案的密文结构,根据模数的分解特点展开模运算。结果与结论运算结果表明,如果模数是合数,且有一个小因数,则没有解密权限的用户可以成功得到明文,验证了模数为素数的必要性,为格上属性基加密方案的设计提供理论参考。

Purposes—To analyze the effect of modulus selection on security in BGG^(+)14 attribute-based encryption scheme.Methods—By assuming the modulus to be composite and setting joint error vector,the ciphertext structure of the BGG^(+)14 attribute-based encryption scheme is utilized to perform modulo operations in accordance with the decomposition characteristics of the modulus.Results and Conclusions—The arithmetic results show that if the modulus is composite and has a small factorization,an adversary without decryption permission can successfully obtain the plaintext.Therefore,it is verified that the modulus must be prime,and some theoretical references for attribute-based encryption scheme based on lattices are provided.