Abstract: Against the backdrop of growing widespread adoption of data sharing and cloud computing technologies, the simultaneous realization of data privacy protection, flexible access control, and controlled computation over ciphertext has emerged as a key research area in the field of information security. Attribute-Based Inner Product Functional Encryption (ABIPFE) integrates the respective strengths of attribute-based encryption and functional encryption. Nevertheless, the majority of existing ABIPFE schemes are constructed based on static access structures, and cannot support the reuse of original ciphertexts when access policies evolve. This deficiency results in progressively increasing computational and communication overhead when such schemes are deployed in dynamic environments. To resolve this problem, this paper proposes an attribute-based inner product functional encryption scheme that supports dynamic expansion of access structures. This scheme incorporates two categories of extended encryption mechanisms. Instead of re-encrypting the original ciphertexts, the proposed scheme only generates additional ciphertext components for the newly added access structure parts, which effectively reduces the overall system overhead. Experimental implementation and performance evaluation demonstrate that across different attribute scales, message dimensions, and expansion depths, the proposed scheme outperforms the comparison schemes in the key generation, encryption, and decryption phases, while maintaining stable overall operation.

Key words: attribute-based encryption; functional encryption; inner-product encryption; hierarchical access structure; dynamic access control

摘要： 在数据共享与云计算不断普及的背景下，保障数据隐私的同时实现灵活的访问控制与密文上受控计算，已成为信息安全领域的重要研究课题。属性内积函数加密（Attribute-Based Inner Product Functional Encryption，ABIPFE）结合了属性加密与函数加密的优点，然而现有方案多基于静态访问结构，不支持策略演化过程中的密文复用，导致在动态环境中计算和通信开销不断增加。针对上述问题，本文提出了一种支持访问结构动态扩展的属性内积函数加密方案，引入两类扩展加密机制，在不重新加密原有密文的前提下，对新增部分生成密文组件，降低系统的整体开销。实验与评测表明，在不同属性规模、消息维度与扩展深度下，该方案在密钥生成、加密、解密阶段相较对比方案性能更优，且整体运行稳定。

关键词: 属性加密；函数加密；内积加密；分层访问结构；动态访问控制