International Association for Cryptologic Research

International Association
for Cryptologic Research


Receiver-Anonymity in Rerandomizable RCCA-Secure Cryptosystems Resolved

Yi Wang , National University of Defense Technology
Rongmao Chen , National University of Defense Technology
Guomin Yang , University of Wollongong
Xinyi Huang , Fujian Normal University
Baosheng Wang , National University of Defense Technology
Moti Yung , Columbia University
DOI: 10.1007/978-3-030-84259-8_10 (login may be required)
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Conference: CRYPTO 2021
Abstract: In this work, we resolve the open problem raised by Prabhakaran and Rosulek at CRYPTO 2007, and present the first anonymous, rerandomizable, Replayable-CCA (RCCA) secure public key encryption scheme. This solution opens the door to numerous privacy-oriented applications with a highly desired RCCA security level. At the core of our construction is a non-trivial extension of smooth projective hash functions (Cramer and Shoup, EUROCRYPT 2002), and a modular generic framework developed for constructing Rand-RCCA-secure encryption schemes with receiver-anonymity. The framework gives an enhanced abstraction of the original Prabhakaran and Rosulek’s scheme (which was the first construction of Rand-RCCA-secure encryption in the standard model), where the most crucial enhancement is the first realization of the desirable property of receiver-anonymity, essential to privacy settings. It also serves as a conceptually more intuitive and generic understanding of RCCA security, which leads, for example, to new implementations of the notion. Finally, note that (since CCA security is not applicable to the privacy applications motivating our work) the concrete results and the conceptual advancement presented here, seem to substantially expand the power and relevance of the notion of Rand-RCCA-secure encryption.
Video from CRYPTO 2021
  title={Receiver-Anonymity in Rerandomizable RCCA-Secure Cryptosystems Resolved},
  author={Yi Wang and Rongmao Chen and Guomin Yang and Xinyi Huang and Baosheng Wang and Moti Yung},