基于双线性映射可撤销用户的叛逆者追踪方案是对称方案,但没有提供不可否认性.针对此问题,利用不经意多项式估值(OPE)协议和服务参数提出了一个改进的方案.改进方案在保持与原方案性能大体相同的前提下。增加了提供多种服务、用户无法抵赖其叛逆行为和数据提供商无法陷害无辜用户等优点;同样在判定双线性DiffieHellman(DBDH)问题的假设下,证明了改进方案是语义上安全的.
To et al. presented a bilinear-map-based traitor tracing scheme with revocation, but it is a symmetric scheme because it does not provide non-repudiation. An improved To scheme was proposed using oblivious polynomial evaluation (OPE) protocol and service parameters. Under the precondition of general sameness capabilities of both To's and improved To's scheme, the new scheme adds some advantages such as providing multi-service capability, user's non-repudiation and data provider' s noframing innocent users. Furthermore, it is also proved to be semantically secure under the decisional bilinear Diffie-Hellman problem (DBDH) assumption.