Trustworthy and Private Keyword Search in Encrypted Decentralized Storage


We have developed a novel encrypted decentralized storage architecture that provides private, reliable and searchable file-outsourcing services without the need of a centralized trust party.

  • Trustworthy and Private Keyword Search in Encrypted Decentralized Storage
Research completion
Commercialisation opportunities
technology licensing agreement
Problem addressed

Today's decentralized storage service relies on end-to-end encryption to secure data content and access control, but data encryption prohibits from searching and computing over encrypted data, which inevitably degrades the user experience. In the meantime, decentralized storage commonly faces severe threats from both clients and service peers. Service peers may return partial or incorrect results, while clients may intentionally slander the service peers to avoid payments.

  • Applying searchable encryption techniques to the decentralized setting to enable encrypted decentralized search functions.
  • Incentivizing honest behaviors by utilizing the smart contracts to devise a fair protocol to handle disputes and issue fair payments
Key impact
  • First encrypted decentralized storage design that supports private and trustworthy keyword search function
  • Dynamic efficient searchable encryption scheme with novel protocol that properly adjusts the decentralized storage structure and ensures fairness in a malicious setting
  • Integrated off-chain on-chain protocol for blockchain cost optimizations
  • Public verifiability for searchable encryption schemes
  • A new decentralized storage architecture with encrypted search functions
  • Faciliated and fair payment among individual service peers and user clients
  • Dynamic and publicly verifiable search over outsourced encrypted data


  • US patent: US11,170,114
City University of Hong Kong (CityU)

As one of the fastest growing universities in the world over the past decade, City University of Hong Kong (CityU) is recognised as a hub for innovation in research and professional education. CityU identifies solutions to critical global challenges by extending the frontiers of knowledge both within and beyond existing research paradigms.

The University’s highly qualified academics are drawn from all over the world, not only bringing a wealth of research and professional experience to the teaching programmes, but also contributing to the knowledge and technology advancement.