Biblio
CP-ABE (Ciphertext-policy attribute based encryption) is considered as a secure access control for data sharing. However, the SK(secret key) in most CP-ABE scheme is generated by Centralized authority(CA). It could lead to the high cost of building trust and single point of failure. Because of the characters of blockchain, some schemes based on blockchain have been proposed to prevent the disclosure and protect privacy of users' attribute. Thus, a new CP-ABE identity-attribute management(IAM) data sharing scheme is proposed based on blockchain, i.e. IAM-BDSS, to guarantee privacy through the hidden policy and attribute. Meanwhile, we define a transaction structure to ensure the auditability of parameter transmission on blockchain system. The experimental results and security analysis show that our IAM-BDSS is effective and feasible.
Mobile Ad-hoc Networks (MANETs) have attracted lots of concerns with its widespread use. In MANETs, wireless nodes usually self-organize into groups to complete collaborative tasks and communicate with one another via public channels which are vulnerable to attacks. Group key management is generally employed to guarantee secure group communication in MANETs. However, most existing group key management schemes for MANETs still suffer from some issues, e.g., receiver restriction, relying on a trusted dealer and heavy certificates overheads. To address these issues, we propose a group key management scheme for MANETs based on an identity-based authenticated dynamic contributory broadcast encryption (IBADConBE) protocol which builds on an earlier work. Our scheme abandons the certificate management and does not need a trusted dealer to distribute a secret key to each node. A set of wireless nodes are allowed to negotiate the secret keys in one round while forming a group. Besides, our scheme is receiver-unrestricted which means any sender can flexibly opt for any favorable nodes of a group as the receivers. Further, our scheme satisfies the authentication, confidentiality of messages, known-security, forward security and backward security concurrently. Performance evaluation shows our scheme is efficient.