A algorithm of fully homomorphic encryption

Among so many cryptographies, homomorphice encryption has attracted widely attentions from scholars for its special performance. Common cryptography can´t directly calculate on encrypted data, but homomorphic encryption can, meanwhile, the operation results of homomorphic encryption will be automatically encrypted. The application prospect of homomorphic encryption is widely and cheerful in the fields of secure multi-party computation, electronic voting, ciphertext searching, encrypted mail filtering, mobile cipher. In the paper, the interrelated technique is discribed and a modified ElGamal Encryption is introduced. The modified Encryption can meet multiplicative homomorphism and additive homomorphism and advance security. Finally, security analysis is test and farther research way is pointed out.