Research And Implementation Of Identity-based Encryption Scheme

Identity-based encryption(IBE)systems is public-key cryptosystem,the generation of ciphertext and key are related to identity ID.The encryptor encrypts the plaintext using the public key,where the public key is the recipient's identity ID and a set of public parameters,and the recipient's identity ID can be any character string,such as an email address or other identifier.The decrypter(the receiver)can decrypt the ciphertext only by using the private key generated by the corresponding identity ID,the private key of the user is generated by the key generation center(PKG).The key generation center(PKG)owns a master key.After the user verifies the identity,the key generation center(PKG)uses the master key for the private key corresponding to his identity and sends it to the user.The work completed in this paper is divided into two aspects as following:(1)Research and implement five identity-based encryption schemes,and analyze as well as compare the advantages and disadvantages and efficiency of these five schemes;(2)We present a more secure and efficient Identity-based dual-system encryption scheme.This scheme is obtained by improving the security proof in the Gentry scheme.The proof of security in the Gentry scheme adoptes partition strategy technology.The proof of security is related to the number of private key queries issued by the adversary.The identity-based encryption scheme proposed in this thesis basically maintains the original structure,thus maintaining the high efficiency of the original scheme,the shorter public parameters,realizing anonymity,and uses dual system encryption technology to prove that the program is completely secure.Finally the program was implemented by Java programming language.Comparing the proposed scheme with the scheme[11] and scheme[12],the efficiency of the proposed scheme is more efficient.