Key Updatable Hash Based VRF

Paper 2026/052

Key Updatable Hash Based VRF

Suman Ghosh

, Indian Institute of Technology Kharagpur

Ratna Dutta, Indian Institute of Technology Kharagpur

Sourav Mukhopadhyay, Indian Institute of Technology Kharagpur

Abstract

Unbiased, unpredictable, and publicly verifiable randomness is essential for a wide range of blockchain-based Web3 applications. Verifiable Random Functions (VRFs) naturally satisfy these requirements. For practical deployment, however, a VRF scheme must support efficient key generation and allow multiple evaluations across different blockchain rounds. In this work, we present a post-quantum secure, key-updatable VRF construction built from symmetric cryptographic primitives, including hash functions and pseudorandom generators (PRGs). The core of our design is a quantum-secure Extended Merkle Signature Scheme (XMSS) structured over multiple layers. We reorganize the XMSS framework in a systematic way to integrate it seamlessly into our VRF construction. Compared to existing approaches, our scheme offers improved key generation efficiency while enabling multiple evaluations from a single secret–verification key pair.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint.
Keywords: Post-Quantum Verifiable Random Function Hash Merkle Tree Blockchain Algorand
Contact author(s): sg7 @ kgpian iitkgp ac in
ratna @ maths iitkgp ac in
sourav @ maths iitkgp ac in
History: 2026-02-27: last of 2 revisions; 2026-01-13: received; See all versions
Short URL: https://ia.cr/2026/052
License: CC BY

BibTeX

@misc{cryptoeprint:2026/052,
      author = {Suman Ghosh and Ratna Dutta and Sourav Mukhopadhyay},
      title = {Key Updatable Hash Based {VRF}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/052},
      year = {2026},
      url = {https://eprint.iacr.org/2026/052}
}