Cryptology ePrint Archive: Report 2019/1078

Puncturable Proxy Re-Encryption supporting to Group Messaging Service

Tran Viet Xuan Phuong and Willy Susilo and Jongkil Kim and Guomin Yang and Dongxi Liu

Abstract: This work envisions a new encryption primitive for many-to-many paradigms such as group messaging systems. Previously, puncturable encryption (PE) was introduced to provide forward security for asynchronous messaging services. However, existing PE schemes were proposed only for one-to-one communication, and causes a significant overhead for a group messaging system. In fact, the group communication over PE can only be achieved by encrypting a message multiple times for each receiver by the sender's device, which is usually suitable to restricted resources such as mobile phones or sensor devices. Our new suggested scheme enables to re-encrypt ciphertexts of puncturable encryption by a message server (i.e., a proxy) so that computationally heavy operations are delegated to the server who has more powerful processors and a constant power source. We then proposed a new Puncturable Proxy Re-Encryption (PPRE) scheme. The scheme is inspired by unidirectional proxy re-encryption (UPRE), which achieves forward secrecy through fine-grained revocation of decryption capability by integrating the PE scheme. This paper first presents a forward secure PPRE in the group messaging service. Our scheme is IND-CCA secure under 3-weak Decision Bilinear Diffie-Hellman Inversion assumption

Category / Keywords: public-key cryptography / Puncturable Encryption, Proxy Re-Encryption, Group Messaging Service, CCA Security

Original Publication (with minor differences): ESORICS

Date: received 20 Sep 2019

Contact author: txuan at uow edu au

Available format(s): PDF | BibTeX Citation

Note: Minor typos

Version: 20190923:091917 (All versions of this report)

Short URL: ia.cr/2019/1078


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