Ciphertext policy attribute-based encryption (CP-ABE) is an encryption mechanism that can provide fine-grained access control and adequate cloud storage security for Internet of Things (IoTs). In this field, the original CP-ABE scheme usually has only a single trusted authority, which will become a bottleneck in IoTs. In addition, different users may illegally share their private keys to obtain improper benefits. Besides, the data owners also require the flexibility to change their access policy. In this paper, we construct a multiauthority CP-ABE scheme on prime order groups over a large attribute universe. Our scheme can support white-box traceability along with policy updates to solve the abovementioned three problems and, thus, can fix the potential requirements of IoTs. More precisely, the proposed scheme supports multiple authority, white box traceability, large attribute domains, access policy updates, and high expressiveness. We prove that our designed scheme is static secure and traceable secure based on the state-of-the-art security models. Moreover, by theoretical comparison, our scheme has better performance than other schemes. Finally, extensive experimental comparisons show that our proposed algorithm can be better than the baseline algorithms.

中文翻译：

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基于多权限属性的加密和可更新的动态策略

基于密文策略属性的加密（CP-ABE）是一种加密机制，可以为物联网（IoT）提供细粒度的访问控制和足够的云存储安全性。在这一领域，原始的CP-ABE方案通常只有一个受信任的授权机构，这将成为物联网的瓶颈。此外，不同的用户可能会非法共享其私钥，以获得不正当利益。此外，数据所有者还需要灵活地更改其访问策略。在本文中，我们在大型属性宇宙上的素数阶上构造了一个多权限CP-ABE方案。我们的方案可以支持白盒可追溯性以及策略更新，以解决上述三个问题，从而可以解决物联网的潜在需求。更准确地说，建议的方案支持多种权限，白盒可追溯性，较大的属性域，访问策略更新和高表达能力。我们证明，根据最新的安全模型，我们设计的方案是静态安全的和可追溯的安全。而且，通过理论比较，我们的方案具有比其他方案更好的性能。最后，大量的实验比较表明，我们提出的算法可以比基线算法更好。