Registration-Based Encryption from Standard Assumptions

Garg, S and Hajiabadi, M and Mahmoody, M and Rahimi, A and Sekar, S (2019) Registration-Based Encryption from Standard Assumptions. In: 22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2019, 14 - 17 April 2019, Beijing, pp. 63-93.

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Abstract

The notion of Registration-Based Encryption (RBE) was recently introduced by Garg, Hajiabadi, Mahmoody, and Rahimi [TCC’18] with the goal of removing the private-key generator (PKG) from IBE. Specifically, RBE allows encrypting to identities using a (compact) master public key, like how IBE is used, with the benefit that the PKG is substituted with a weaker entity called “key curator” who has no knowledge of any secret keys. Here individuals generate their secret keys on their own and then publicly register their identities and their corresponding public keys to the key curator. Finally, individuals obtain “rare” decryption-key updates from the key curator as the population grows. In their work, they gave a construction of RBE schemes based on the combination of indistinguishability obfuscation and somewhere statistically binding hash functions. However, they left open the problem of constructing RBE schemes based on standard assumptions. In this work, we resolve the above problem and construct RBE schemes based on standard assumptions (e.g., CDH or LWE). Furthermore, we show a new application of RBE in a novel context. In particular, we show that anonymous variants of RBE (which we also construct under standard assumptions) can be used for realizing abstracts forms of anonymous messaging tasks in simple scenarios in which the parties communicate by writing messages on a shared board in a synchronized way.

Item Type:	Conference Paper
Publication:	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Publisher:	Springer Verlag
Additional Information:	The copyright for this article belongs to Springer Verlag.
Keywords:	Chromium compounds; Hash functions, Indistinguishability; Key updates; New applications; Private key generators; Public keys; Secret key; Standard assumptions, Public key cryptography
Department/Centre:	Division of Physical & Mathematical Sciences > Mathematics
Date Deposited:	17 Nov 2022 06:20
Last Modified:	17 Nov 2022 06:20
URI:	https://eprints.iisc.ac.in/id/eprint/77972

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