In a common authentication code with arbitration, the dishonest arbiter may make a threat to the security of authentication system. In this paper, an authentication code with double arbiters over symplectic geometry is constructed, and the relevant parameters and the probabilities of successful attacks are calculated. The model not only prevents deception from the opponent and members of the system, but also effectively limits the attacks of single arbiter. Moreover, the collusion attacks from arbiters and participators are difficult to succeed.
To achieve secure communication in wireless sensor networks （WSNs）, where sensor nodes with limited computation capability are randomly scattered over a hostile territory, various key pre-distribution schemes （KPSs） have been proposed. In this paper, a new KPS is proposed based on symplectic geometry over finite fields. A fixed dimensional subspace in a symplectic space represents a node, all 1-dimensional subspaces represent keys and every pair of nodes has shared keys. But this naive mapping does not guarantee a good network resiliency. Therefore, it is proposed an enhanced KPS where two nodes have to compute a pairwise key, only if they share at least q common keys. This approach enhances the resilience against nodes capture attacks. Compared with the existence of solution, the results show that new approach enhances the network scalability considerably, and achieves good connectivity and good overall performance.
Through cryptanalysis of the improved scheme of a generalized group-oriented threshold signcryption schemes,it is found that the improved scheme can effectively resist conspiracy attack and forgery attack,but does not have semantic security and public verification function,and sends threshold signcryption by the secret secure channel,which increases the communication costs and potential safety hazards of the system.A new group-oriented publicly verifiable threshold signcryption scheme is proposed on the basis of the improved scheme,the new scheme overcomes the drawbacks of the improved scheme,which not only provides with semantic security and public verification function,but also can send threshold signcryption by the public channel.
