Secure Provenance of Electronic Records Based on Blockchain

At present,the provenance of electronic records is stored centrally.The centralized way of information storage has huge risks.Whether the database itself is destroyed or the communication between the central database and the external interruption occurs,the provenance information of the stored electronic records will not play its role.At the same time,uncertainties such as fires and earthquakes will also pose a potential threat to centralized databases.Moreover,the existing security provenance model is not specifically designed for electronic records.In this paper,a security provenance model of electronic records is constructed based on PREMIS and METS.Firstly,this paper analyses the security requirements of the provenance information of electronic records.Then,based on the characteristics of blockchain decentralization,and combined with coding theory,a distributed secure provenance guarantees technology of electronic records is constructed,which ensures the authenticity,integrity,confidentiality and reliability of the provenance information.

Identity-based signature scheme based on quadratic residues

Identity-based （ID-based） cryptography has drawn great concerns in recent years, and most of ID-based schemes are constructed from bilinear parings. Therefore, ID-based scheme without pairing is of great interest in the field of cryptography. Up to now, there still remains a challenge to construct ID-based signature scheme from quadratic residues. Thus, we aim to meet this challenge by proposing a concrete scheme. In this paper, we first introduce the technique of how to calculate a 2^lth root of a quadratic residue, and then give a concrete ID-based signature scheme using such technique. We also prove that our scheme is chosen message and ID secure in the random oracle model, assuming the hardness of factoring.

Efficient ID-Based Multi-Decrypter Encryption with Short Ciphertexts

Multi-decrypter encryption is a typical application in multi-user cryptographic branches. In multi-decrypter encryption, a message is encrypted under multiple decrypters＇ public keys in the way that only when all the decrypters cooperate, can the message be read. However, trivial implementation of multi-decrypter encryption using standard approaches leads to heavy computation costs and long ciphertext which grows as the receiver group expands. This consumes much precious bandwidth in wireless environment, such as mobile ad hoc network. In this paper, we propose an efficient identity based multi-decrypter encryption scheme, which needs only one or zero （if precomputed） pairing computation and the ciphertext contains only three group elements no matter how many the receivers are. Moreover, we give a formal security definition for the scheme, and prove the scheme to be chosen ciphertext secure in the random oracle model, and discuss how to modify the scheme to resist chosen ciphertext attack.