The “13th Five-Year” National Crypto Development Foundation (MMJJ20170122); The National Natural Science Foundation of China(61802117); The Projects of Henan Provincial Department of Science and Technology(192102210280)
针对恶意用户出售私钥后难以被追责的问题，同时考虑到实际应用中用户属性存在重要程度不同的需求，提出一种支持叛逆者追踪的权重属性基加密方案，该方案将用户身份信息嵌入到用户的私钥中，从而追踪系统中泄露关键信息的恶意用户。另外将属性权重的思想引入该方案，将属性集通过属性集分割算法转化为属性权重的分割集，采用线性秘密共享实现访问控制，使其更贴近于实际环境。方案证明在q-BDHE(q-bilinear diffie-hellman exponent)假设下满足标准模型下选择明文攻击安全。与其他方案相比，该方案在通信代价和计算代价方面都有显著的提高，更加适用于移动终端设备在云计算中的应用。
In practical applications of traditional attribute based encryption scheme, it is difficult to track the malicious user who sells his private keys. And, the user attributes can’t show the level of identity. To solve the problem, a weighted attribute-based encryption scheme with traitor tracing is proposed. In the scheme, the user’s private key which contains the user identity information is used to trace traitors. In addition, the idea of attribute weight is adopted, and the attribute set is transformed into the segmentation set of attribute weight through the attribute set segmentation algorithm. The proposed scheme provides fine-grained and flexible access control based on linear secret sharing. It is proved to be secure against chosen plaintext attack under the q-decisional bilinear diffie-hellman assumption in the standard model. Compared with other related schemes, it has significant improvement in communication and computing cost, and it is more suitable for the application of mobile terminal in cloud computing.