Research On Hierarchical Identity-Based Cryptography Scheme

In the standard model,the cryptographic study is to solve the idealized security proof under the random oracle model.In fact,the random oracle model does not achieve an idealized security proof.In the practical application,the standard model demonstrates the security of the scheme based on some mathematical problem and has practical significance.Cryptographic research under the standard model can be applied to many scenarios,such as e-commerce,efficient storage in cloud computing,and identity authentication.This paper mainly uses formal definition and security proof to organize the program.The main work is as follows:(1)This paper constructed an hierarchical identity-based encryption(HIBE)scheme,in order to solve the problem of privacy deployment and efficiency management in data sharing system,which achieved the indistinguishability of selecting identity and selecting plaintext attack security under the standard model(IND-CIVS-CPA).In this scheme,four static hypotheses were used to construct a private key for elements in different prime numbers,generated a short fixed ciphertext,and decrypted it correctly.The experimental results show that the CPA security hierarchical encryption scheme has three fixed ciphertexts,only two bilinear pairs are calculated,and the scheme of the same type is efficient.Converted to a compact CCA2 secure HIBE solution based on the proposed CPA-safe HIBE solution.In this scenario,we virtualized the root node,and any adversary could't get the private key of the virtual(PKG root node),but it could be used to check whether the ciphertext is valid.In the experimental results,compared with the CPA-safe HIBE scheme,the exponential operation and the multiplication operation in the encryption algorithm are the same,but one more hash operation.In the decryption algorithm,the exponential operation is the same as the multiplication operation,but the operation of the bilinear pair is two more times.Although the computational overhead has increased,the selective identity of the scheme and the indistinguishability of the selected ciphertext attack(IND-CIVS-CCA2)have been achieved.(2)Based on CPA security HIBE,a general identity-based hierarchical signature scheme was constructed.In this scenario,the supervisor user could delegate private key generation and signature verification to subordinate users.Under the standard model,using the dual-system technique,this scheme proved that the selection of identity vectors and the selection of ciphertext attacks were unforgeable(EF-CMA).The experimental results show that the scheme has a short private key length and signature length and low computational overhead,and is highly efficient.