LowMC在BGV全同态加密环境下的噪声评估OA北大核心CSTPCD

The ciphertext computing characteristics of full homomorphic encryption technology can effectively protect users'sensitive data on the Internet,but the problem of ciphertext inflation in this technology is a difficulty that restricts its practical application in fields such as cloud computing and privacy protection.In response to the above issues,this article proposes a hybrid homomorphic encryption scheme FHE-LowMC,which combines the LowMC symmetric encryption algorithm with the BGV homomorphic encryption algorithm to analyze the homomorphic noise of LowMC in the BGV homomorphic encryption environment.First,a method for encoding the LowMC plaintext into integer coefficient polynomials is proposed,which utilizes encoding and decoding to complete the conversion of plaintext messages in different spaces.Then,the selection rules for the cyclotomic polynomial f(X)is described,with the conditions f(X)suitable for the LowMC encryption algorithm given.Afterwards,the homomorphic noise of the simplified LowMC is analyzed.Finally,homomorphic noise evaluation is performed on LowMC under general conditions.The results show that the number of circuit layers consumed by the LowMC round function is about two.Compared with the currently commonly used AES and BGV combination scheme,the scheme combining LowMC and BGV has a lower noise,which means it consumes fewer layers of circuits and has lower costs,making it more suitable for constructing cloud servers based on homomorphisms.In addition,users can independently select the parameter set(n～,k,m,d)of LowMC,which meets the different needs of users and has a wider scope of application.