Extended Asymmetric Group Key Agreement for Dynamic Groups and Its Applications

Group Key Agreement(GKA)is a cryptographic primitive allowing two or more entities to negotiate a shared session key over public networks.In existing GKA models,it is an open problem to construct a one-round multi-party GKA protocol.Wu et al.recently proposed the concept of asymmetric group key agreement(ASGKA)and realized a one-round ASGKA protocol,which affirmatively answers the above open problem in a relaxed way.However,the ASGKA protocol only applies to static groups.To fill this gap,this paper proposes an extended ASGKA protocol based on the Wu et al.protocol.The extension allows any member to join and leave at any point,provided that the resulting group size is not greater than n.To validate the proposal,extensive experiments are performed and the experimental results show that our protocol is more effective than a plain realization of the Wu et al.protocol for dynamic groups.The extended protocol is also more efficient than the up-to-date dynamic GKA protocol in terms of communication and computation.

Navigating the Quantum Threat Landscape: Addressing Classical Cybersecurity Challenges

This research paper analyzes the urgent topic of quantum cybersecurity and the current federal quantum-cyber landscape. Quantum-safe implementations within existing and future Internet of Things infrastructure are discussed, along with quantum vulnerabilities in public key infrastructure and symmetric cryptographic algorithms. Other relevant non-encryption-specific areas within cybersecurity are similarly raised. The evolution and expansion of cyberwarfare as well as new developments in cyber defense beyond post-quantum cryptography and quantum key distribution are subsequently explored, with an emphasis on public and private sector awareness and vigilance in maintaining strong security posture.

SSEM： Secure, Scalable and Efficient Multi-Owner Data Sharing in Clouds

Data sharing is a main application of cloud computing. Some existing solutions are proposed to provide flexible access control for outsourced data in the cloud. However, few attentions have been paid to group-oriented data sharing when multiple data owners want to share their private data for cooperative purposes. In this paper, we put forward a new paradigm, referred to as secure, scalable and efficient multi-owner(SSEM) data sharing in clouds. The SSEM integrates identity-based encryption and asymmetric group key agreement to enable group-oriented access control for data owners in a many-to-many sharing pattern. Moreover, with SSEM, users can join in or leave from the group conveniently with the privacy of both group data and user data.We proposed the key-ciphertext homomorphism technique to construct an SSEM scheme with short ciphertexts. The security analysis shows that our SSEM scheme achieves data security against unauthorized accesses and collusion attacks. Both theoretical and experimental results confirm that our proposed scheme takes users little costs to share and access outsourced data in a group manner.