With the rise of cloud computing, secure and efficient data sharing has become essential, especially when handling sensitive information. This project implements a secure key-aggregate keyword retrieval scheme, allowing encrypted files to be shared and searched in a privacy-preserving manner. Data owners can upload encrypted documents, generate an aggregate secret key, and share specific files with authorized data users. The data users, in turn, can search for desired documents by keywords without revealing either the search terms or the content of the documents to the cloud server. The system ensures semantic security against keyword guessing attacks by leveraging linear splitting and trapdoor re-randomization techniques. In addition, a Zero-Knowledge Proof (ZKP) extension algorithm is introduced, providing further privacy guarantees by allowing the verification of search correctness without revealing any sensitive data. This approach enhances privacy and scalability, ensuring robust access control and secure data retrieval in cloud environments.

Keywords:
Key-aggregate encryption, keyword search, cloud computing, data privacy, secure file sharing, trapdoor generation, searchable encryption, semantic security, access control, encrypted data retrieval, Zero-Knowledge Proof (ZKP), privacy-preserving search, cryptographic techniques, aggregate key, cloud data sharing.