Biblio

Identity based digital signature is an important research topic of public key cryptography, which can effectively guarantee the authentication, integrity and unforgeability of data. In this paper, a new fuzzy multi-identity based signature scheme is proposed. It is proved that the scheme is existentially unforgeable against adaptively chosen message attack, and the security of the signature scheme can be reduced to CDH assumption. The storage cost and the communication overhead are small, therefore the new fuzzy multi-identity based signature (FMIBS) scheme can be implemented efficiently.

SWIM (System Wide Information Management) has become the development direction of A TM (Air Traffic Management) system by providing interoperable services to promote the exchange and sharing of data among various stakeholders. The premise of data sharing is security, and the access control has become the key guarantee for the secure sharing and exchange. The CP-ABE scheme (Ciphertext Policy Attribute-Based Encryption) can realize one-to-many access control, which is suitable for the characteristics of SWIM environment. However, the combination of the existing CP-ABE access control and SWIM has following constraints. 1. The traditional single authority CP-ABE scheme requires unconditional trust in the authority center. Once the authority center is corrupted, the excessive authority of the center may lead to the complete destruction of system security. So, SWIM with a large user group and data volume requires multiple authorities CP-ABE when performing access control. 2. There is no unified management of users' data access records. Lack of supervision on user behavior make it impossible to effectively deter malicious users. 3. There are a certain proportion of lightweight data users in SWIM, such as aircraft, users with handheld devices, etc. And their computing capacity becomes the bottleneck of data sharing. Aiming at these issues above, this paper based on cloud-chain fusion basically proposes a multi-authority CP-ABE scheme, called the MOV ATM scheme, which has three advantages. 1. Based on a multi-cloud and multi-authority CP-ABE, this solution conforms to the distributed nature of SWIM; 2. This scheme provides outsourced computing and verification functions for lightweight users; 3. Based on blockchain technology, a blockchain that is maintained by all stakeholders of SWIM is designed. It takes user's access records as transactions to ensure that access records are well documented and cannot be tampered with. Compared with other schemes, this scheme adds the functions of multi-authority, outsourcing, verifiability and auditability, but do not increase the decryption cost of users.

Access authentication is a key technology to identify the legitimacy of mobile users when accessing the space-ground integrated networks (SGIN). A hierarchical identity-based signature over lattice (L-HIBS) based mobile access authentication mechanism is proposed to settle the insufficiencies of existing access authentication methods in SGIN such as high computational complexity, large authentication delay and no-resistance to quantum attack. Firstly, the idea of hierarchical identity-based cryptography is introduced according to hierarchical distribution of nodes in SGIN, and a hierarchical access authentication architecture is built. Secondly, a new L-HIBS scheme is constructed based on the Small Integer Solution (SIS) problem to support the hierarchical identity-based cryptography. Thirdly, a mobile access authentication protocol that supports bidirectional authentication and shared session key exchange is designed with the aforementioned L-HIBS scheme. Results of theoretical analysis and simulation experiments suggest that the L-HIBS scheme possesses strong unforgeability of selecting identity and adaptive selection messages under the standard security model, and the authentication protocol has smaller computational overhead and shorter private keys and shorter signature compared to given baseline protocols.