The Cost of Quantum Resistance: A Hash-Based Commit-Reveal Alternative for Minimizing Blockchain Infrastructure Overhead

Computer Science > Cryptography and Security [Submitted on 7 May 2026] The Cost of Quantum Resistance: A Hash-Based Commit-Reveal Alternative for Minimizing Blockchain Infrastructure Overhead Keir Finlow-Bates, Markus Jakobsson, Hossein Siadati The transition to post-quantum cryptography in blockchain systems such as Bitcoin and Ethereum is often framed as a purely cryptographic problem. In practice, it also presents significant economic and infrastructural challenges: in globally replicated networks, increases in transaction size and verification cost are multiplied across all participating nodes. Existing post-quantum signature schemes, including lattice-based constructions such as CRYSTALS-Dilithium and stateless hash-based schemes such as SPHINCS+, introduce substantial increases in signature size. At blockchain scale, these increases translate into higher storage, bandwidth, and validation requirements, potentially requiring multiple generations of hardware improvement to become operationally routine. Historical experience suggests that even moderate increases in data footprint can be contentious, as illustrated by the Bitcoin block size debates (2015--2017). We propose a hash-based commit--reveal construction that replaces a single signature-bearing transaction with two lightweight transactions, each containing a fixed-size (32-byte) hash output derived from well-established primitives such as SHA-256, BLAKE, or Keccak. This approach achieves post-quantum security under standard hash assumptions while increasing the effective transaction footprint by only approximately 1.5\times to 2\times per authorization event. These results indicate that practical post-quantum migration may benefit from rethinking transaction semantics rather than directly adopting larger signature schemes, and that viable designs for decentralized systems must account for system-wide cost amplification. Comments: 20 pages, 2 tables, 2 figures Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2605.06853 [cs.CR]   (or arXiv:2605.06853v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2605.06853 Focus to learn more Submission history From: Markus Jakobsson [view email] [v1] Thu, 7 May 2026 18:53:14 UTC (283 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-05 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)