Paper 2024/628
MUSEN: Aggregatable Key-Evolving Verifiable Random Functions and Applications
Abstract
A Verifiable Random Function (VRF) can be evaluated on an input by a prover who holds a secret key, generating a pseudorandom output and a proof of output validity that can be verified using the corresponding public key. VRFs are a central building block of committee election mechanisms that sample parties to execute tasks in cryptographic protocols, e.g. generating blocks in a Proof-of-Stake (PoS) blockchain or executing a round of MPC protocols. We propose the notion, and a matching construction, of an Aggregatable Key-Evolving VRF (A-KE-VRF) with the following extra properties: 1. Aggregation: combining proofs for several VRF evaluations of different inputs under different secret keys into a single constant size proof; 2. Key-Evolving: preventing adversaries who corrupt a party (learning their secret key) from ``forging'' proofs of past VRF evaluations. As an immediate application, we improve on the block size of PoS blockchains and on the efficiency of Proofs of Proof-of-Stake (PoPoS). Furthermore, the A-KE-VRF notion allows us to construct Encryption to the Future (EtF) and Authentication from the Past (AfP) schemes with a Key-Evolving property, which provides forward security. An EtF scheme allows for sending a message to a party who is randomly selected to execute a role in the future, while an AfP scheme allows for this party to authenticate their messages as coming from a past execution of this role. These primitives are essential for realizing the YOSO MPC Framework (CRYPTO'21).
Note: Added comparison to recent and independent related works.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Major revision. SCN 2024
- Keywords
- Verifiable Random FunctionsYOSO MPCEncryption to the FutureProof-of-StakeBlockchain
- Contact author(s)
-
bernardo @ bmdavid com
rafael dowsley @ monash edu
anders @ espressosys com
mario @ c titech ac jp - History
- 2024-07-08: last of 3 revisions
- 2024-04-24: received
- See all versions
- Short URL
- https://ia.cr/2024/628
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2024/628,
author = {Bernardo David and Rafael Dowsley and Anders Konring and Mario Larangeira},
title = {{MUSEN}: Aggregatable Key-Evolving Verifiable Random Functions and Applications},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/628},
year = {2024},
url = {https://eprint.iacr.org/2024/628}
}