### Public-Key Puncturable Encryption: Modular and Compact Constructions

Shi-Feng Sun, Amin Sakzad, Ron Steinfeld, Joseph Liu, and Dawu Gu

##### Abstract

We revisit the method of designing public-key puncturable encryption schemes and present a generic conversion by leveraging the techniques of distributed key-distribution and revocable encryption. In particular, we first introduce a refined version of identity-based revocable encryption, named key-homomorphic identity-based revocable key encapsulation mechanism with extended correctness. Then, we propose a generic construction of puncturable key encapsulation mechanism from the former by merging the idea of distributed key-distribution. Compared to the state-of-the-art, our generic construction supports unbounded number of punctures and multiple tags per message, thus achieving more fine-grained revocation of decryption capability. Further, it does not rely on random oracles, not suffer from non-negligible correctness error, and results in a variety of efficient schemes with distinct features. More precisely, we obtain the first scheme with very compact ciphertexts in the standard model, and the first scheme with support for both unbounded size of tags per ciphertext and unbounded punctures as well as constant-time puncture operation. Moreover, we get a comparable scheme proven secure under the standard DBDH assumption, which enjoys both faster encryption and decryption than previous works based on the same assumption, especially when the number of tags associated with the ciphertext is large.

Available format(s)
Category
Public-key cryptography
Publication info
A minor revision of an IACR publication in PKC 2020
Keywords
Functional EncryptionPuncturable EncryptionForward Security
Contact author(s)
shifeng sun @ monash edu
ron steinfeld @ monash edu
joseph liu @ monash edu
dwgu @ sjtu edu cn
History
Short URL
https://ia.cr/2020/126

CC BY

BibTeX

@misc{cryptoeprint:2020/126,
author = {Shi-Feng Sun and Amin Sakzad and Ron Steinfeld and Joseph Liu and Dawu Gu},
title = {Public-Key Puncturable Encryption: Modular and Compact Constructions},
howpublished = {Cryptology ePrint Archive, Paper 2020/126},
year = {2020},
note = {\url{https://eprint.iacr.org/2020/126}},
url = {https://eprint.iacr.org/2020/126}
}

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