Cloud storage revolutionizes data management but raises conflicts between functionality and privacy. Public Key Encryption with Equality Test (PKEET), an advanced cryptographic technique, can enable multi-user searchable encryption (SE) through cross-key ciphertext comparison without shared keys. However, existing PKEET-based SE schemes lack ciphertext-file-level authorization, public verifiability, or SE-level support. This paper first proposes a novel PKEET scheme, AVPKEET (Authorized and Verifiable PKEET). It enables non-transferable and non-replayable authorization of ciphertext files, while supporting public verifiability, all without the need for trusted third parties. Then we propose an AVPKEET-based SE scheme, denoted as AVSE (Authorized and Verifiable SE), featuring one-time non-transferable tokens bound to users and nonces, batch operations, and fine-grained access control (ALL, PARTIAL, SINGLE). We prove OW-CCA2 security, token unforgeability, and verification soundness under standard assumptions. Experiment results demonstrate that AVSE achieves the most compact token size (168 bytes) while uniquely providing both ciphertext-file-level authorization and public verification, with acceptable overhead for cloud storage deployment.

翻译：云存储革新了数据管理方式，但却引发了功能性与隐私性之间的矛盾。公钥相等性测试（PKEET）作为一种先进的密码技术，能够在无需共享密钥的情况下，通过跨密钥密文比较实现多用户可搜索加密（SE）。然而，现有的基于PKEET的可搜索加密方案缺乏密文文件级授权、公开可验证性或可搜索加密级别支持。本文首先提出了一种新型PKEET方案——AVPKEET（授权可验证公钥相等性测试）。该方案实现了密文文件的不可转移且不可重放的授权，同时支持公开可验证性，且无需依赖可信第三方。随后，我们提出了一种基于AVPKEET的可搜索加密方案，记为AVSE（授权可验证可搜索加密），其特点包括：绑定用户和随机数的一次性不可转移令牌、批量操作以及细粒度访问控制（全部、部分、单个）。我们证明了在标准假设下方案满足OW-CCA2安全性、令牌不可伪造性以及验证可靠性。实验结果表明，AVSE在实现最紧凑令牌尺寸（168字节）的同时，独特地同时提供了密文文件级授权和公开验证功能，且对于云存储部署具有可接受的性能开销。