Research On Attribute-Based Encryption And Signature Algorithms On Lattices

With the continuous development of cloud computing and information technology,it has become an inevitable choice to outsource data and share resource for either enterprises or individuals.However,the data security problems caused by this are also increasing.Therefore,it is an important issue that how to protect the confidentiality,integrity and authenticity of data with existing technology,which is of widespread concern in the academic community.Meanwhile,with the rappid development of quantum computing,most of the traditional public key encryption and signature schemes cannot resistant quantum attacks,thus are no longer adapt to the new requirements of security and application.Attribute-based cryptosystem achieves flexible and fine-grained access control as well as authentication mechanisms,while protecting the identity privacy of users effectively.In this paper,due to the anti-quantum characteristic of lattice-based cryptosystem,attribute-based encryption(ABE)and digital signature(DS)schemes from lattices are studied for providing fine-grained access control and authentication over data,and a practical multi-authority ciphertext-policy attribute-based encryption on ideal lattices(ILM-CP-ABE)and a fuzzy identity-based signature from module lattices(ML-FIBS)are presented.The main contributions are elaborated as follows:1.A multi-authority ciphertext-policy attribute-based encryption on ideal lattices is constructed.In the scheme,Discrete Fourier Transform is used to improve the efficiency of encryption and decryption,and one-time encryption of multi-bit plaintext is realized.The Shamir threshold secret sharing technology is used to segment and reconstruct the private key of users,which enables the scheme to support the distribution and management of secret key by multiple authority independently.The multi-authoity mechanism significantly reduces the workload of the authorities,improves the efficiency of encryption system,and solves the bottleneck of performance and security in the traditional single-authority encryption systems.Besides,the use of efficient Gaussian preimage sampling algorithm further improves the efficiency of the scheme.2.A fuzzy identity-based signature from module lattices is constructed.In the scheme,a user identity is described as a collection of a series of characteristic attributes,and the trapdoor generation algorithm is used to construct the system public key and master secret key.The technique of trapdoor delegation and preimage sampling algorithm on module lattices are used to construct the user’s private key and signature.Compared with the traditional identity-based signatures,the scheme enriches the expression of identity,realizes fine-grained and redundant identity authentication,and can be directly applied to biometric identity authentication and attribute-based signature systems.In addition,the arithmetic operations in the scheme is on module lattices,which makes it achieves an efficiency similar to that of signatures on ideal lattices,while having higher security and more flexible parameter settings.3.The correctness and security of the above-mentioned lattice-based attribute encryption and digital signature schemes are verified and analyzed.It is proved that the multi-authority ciphertext-policy attribute-based encryption on ideal lattices is selectively secure against Chosen Plaintext Attack(s CPA)under the decisional R-LWE assumption in the standard model,and the fuzzy identity-based signature from module lattices is unforgeable against selectively chosen identity and chosen message attacks(SU-s ID-CMA)in the random oracle model.Through theoretical analysis and simulation experiments,the performance of the above schemes is analyzed and verified.Performance analysis and experimental results shows that the two schemes proposed in this paper can realize efficient encryption and signature processes,while having high application value and practicability.