Secure group communication with both confidentiality and non‐repudiation for mobile ad‐hoc networks

Secure group communication with efficient self‐organising key agreement protocol and small broadcast ciphertext is essential to many collaborative and distributed applications in mobile ad‐hoc networks (MANETs). In this study, the authors propose a Chinese Remainder Theorem‐based secure group communication scheme which is able to provide confidentiality service and non‐repudiation service simultaneously. In the proposed scheme, all group members contribute their own public keys to negotiate a shared encryption public key, which corresponds to all different decryption keys. By using the shared public key and the respective secret key, confidentiality and non‐repudiation can be obtained, respectively. Both are essential to secure group communication in MANETs. Compared with the exiting signcryption schemes for multiple recipients, the proposed self‐organising scheme has much smaller ciphertext that does not increase with the size of the group. Accordingly, it is quite suitable to secure group communication in self‐organising, distributed and resource‐constrained MANETs.