Internet of Things (IoT) is an integration of various technologies to provide technological enhancements. To enforce access control on low power operated battery constrained devices is a challenging issue in IoT scenarios. Attribute-based encryption (ABE) has emerged as an access control mechanism to allow users to encrypt and decrypt data based on an attributes policy. However, to accommodate the expressiveness of policy for practical application scenarios, attributes may be repeated in a policy. For certain policies, the attributes repetition cannot be avoided even after applying the boolean optimization techniques to attain an equivalent smaller length boolean formula. For such policies, the evaluated secret shares are also multiple for repeated attributes; hence, the ciphertext computed for those irreducible policies is long and computational effort is more. To address this issue, a new CP-ABE scheme is proposed which employs our Repeated Attributes Optimization algorithm by which the Linear Secret Sharing Scheme matrix sent along with ciphertext will contain the access structure of policy including attributes appearing multiple times, but the ciphertext will only be evaluated for unique non-repeated attributes. Security and performance analysis show that the proposed construction fulfils its goals of achieving desired security with low communication overhead and computational cost for resource-constrained devices.

物联网（IoT）是各种技术的集成，以提供技术增强。在物联网场景中，对低功耗电池受限设备实施访问控制是一个具有挑战性的问题。基于属性的加密（ABE）已经成为一种访问控制机制，允许用户根据属性策略对数据进行加密和解密。但是，为了适应策略在实际应用场景中的表现力，可以在策略中重复属性。对于某些策略，即使在应用布尔优化技术以获得等效的较小长度的布尔公式后，也无法避免属性重复。对于此类策略，对于重复属性，所评估的秘密份额也为多个。因此，为这些不可约策略计算的密文很长，并且计算量更大。为了解决此问题，提出了一种新的CP-ABE方案，该方案采用了我们的重复属性优化算法，通过该算法，与密文一起发送的线性秘密共享方案矩阵将包含策略的访问结构，其中该属性包括多次出现的属性，但密文只会被评估为唯一的非重复属性。安全性和性能分析表明，所提出的构造以低的通信开销和资源受限设备的计算成本实现了实现所需安全性的目标。提出了一种新的CP-ABE方案，该方案采用了我们的重复属性优化算法，通过该算法，与密文一起发送的“线性秘密共享方案”矩阵将包含策略的访问结构，包括出现多次的属性，但是仅对唯一性-重复的属性。安全性和性能分析表明，对于资源受限的设备，所提出的构造以较低的通信开销和计算成本实现了实现所需安全性的目标。提出了一种新的CP-ABE方案，该方案采用了我们的重复属性优化算法，通过该算法，与密文一起发送的线性秘密共享方案矩阵将包含具有多次出现的属性的策略的访问结构，但仅对唯一性-重复的属性。安全性和性能分析表明，所提出的构造以低的通信开销和资源受限设备的计算成本实现了实现所需安全性的目标。