Bitcoin Core Developer Adam Back Opposes Adoption of Lattice Signatures for Bitcoin
Bitcoin core developer Adam Back stated that lattice signatures are suitable for scenarios like DocuSign but are insufficient to meet Bitcoin's security needs.
He recommends hash-based signature schemes like SHRINCS as a conservative choice, which have decades of peer review, more robust cryptographic hard assumptions, and are easier to understand and build confidence in.
This viewpoint addresses the signature upgrade for Bitcoin in the post-quantum era, emphasizing that the security path should prioritize existing hash function assumptions of Bitcoin rather than introducing new assumptions with lattice schemes.
Source: Public Information
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Adam Back, as the inventor of Hashcash and co-founder of Blockstream, previously led Blockstream Research to publish the "Bitcoin Hash-Based Signature Scheme" paper in December 2025, proposing SHRINCS (a stateful scheme combining SPHINCS+ and XMSS), which has been deployed on the Liquid sidechain via Simplicity smart contracts.
On the capital front, Blockstream mobilizes development investment through research resources and sidechain testing, motivated by the need to maintain Bitcoin's long-term sovereignty against quantum threats, avoiding reliance on NIST-standardized but differently assumed lattice algorithms (like Dilithium), thus protecting the network's consensus layer from potential cryptographic breakthroughs.
Similar cases include the cautious path of Bitcoin's early migration from ECDSA to Schnorr, and Zcash's potential inflation risk due to zero-day vulnerabilities; Bitcoin is currently in a conservative assessment phase for post-quantum readiness, contrasting with traditional financial institutions' rapid adoption of lattice schemes.
Structural judgment: This essentially belongs to an industry chain reconstruction driven by technological substitution. Hash-based schemes embed quantum resistance into the existing trust-minimized architecture by reusing the hash function hard assumptions that Bitcoin already relies on, with the mechanism aimed at avoiding the expanded attack surface caused by introducing new cryptographic primitives, forcing the signature upgrade path to shift from standardized rapid solutions to conservatively validated protocols, thereby maintaining long-term security for decentralized verification.
ABAB News · Law of Cognition
Conservative cryptography surpasses fashionable assumptions; security never chases trends.
The assumptions that systems already rely on are the true credible moats.
The greater the temptation of new technologies, the wiser the reuse of old principles.