Improved security model for public-key authenticated encryption with keyword search

Baodong Qin, Hui Cui, Xiaokun Zheng, Dong Zheng

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

18 Citations (Scopus)


The motivation of public-key authenticated encryption with keyword search (PAEKS) was to resist against inside keyword guessing attacks. Its security model captures both cipher-keyword indistinguishability (CI-security) and trapdoor indistinguishability (TI-security). Recently, this security model was extended from one-user settings to multi-user settings, or from one cipher-keyword indistinguishability to multiple cipher-keyword indistinguishability, making it more practical. However, none of previous CI-security model for PAEKS scheme captures fully chosen keyword to cipher-keyword (CKC) attacks, in which an attacker may obtain cipher-keywords of any keyword (even a challenge keyword) of his choice. Due to this, the paper introduces an improved CI-security model for PAEKS to capture fully CKC attacks in a multi-user setting, and proves that CI-security against fully CKC attacks implies multiple cipher-keyword indistinguishability. Then, the paper proves that some previous PAEKS schemes cannot achieve CI-security under fully CKC attacks. Next, the paper proposes a new PAEKS scheme and proves its CI-security in the improved security model. Finally, the paper demonstrates its comparable security guarantees and computational efficiency by comparing it with previous PAEKS schemes.

Original languageEnglish
Title of host publicationProvable and Practical Security - 15th International Conference, ProvSec 2021 Guangzhou, China, November 5–8, 2021 Proceedings
EditorsQiong Huang, Yu Yu
Place of PublicationCham Switzerland
Number of pages20
ISBN (Electronic)9783030904029
ISBN (Print)9783030904012
Publication statusPublished - 2021
Externally publishedYes
EventInternational Conference on Provable Security 2021 - Guangzhou, China
Duration: 5 Nov 20218 Nov 2021
Conference number: 15th (Proceedings) (Website)

Publication series

NameLecture Notes in Computer Science
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


ConferenceInternational Conference on Provable Security 2021
Abbreviated titleProvSec 2021
Internet address


  • Keyword guessing attacks
  • Searchable encryption
  • Security model

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