Aptos Proposes Quantum-Resistant Signatures to Future-Proof Blockchain Security

Aptos Proposes Quantum-Resistant Signatures to Future-Pro... Aptos unveiled its first post-quantum signature scheme through AIP-137, selecting NIST-standardized SLH-DSA-SHA2-128s to future-proof blockchain security as quantum computing advances compress development timelines and experts project cryptographic threats materializing by the mid-2030s. The post Ap... Aptos has unveiled AIP-137, introducing SLH-DSA-SHA2-128s as its first post-quantum signature scheme to protect against future quantum computing threats. The proposal, drafted by Aptos Labs Head of Cryptography Alin Tomescu, aims to prepare the network for quantum computers that are cryptographically relevant before they become an urgent concern.The initiative arrives as quantum computing transitions from theoretical speculation to tangible reality, with IBM discussing scaling paths and NIST publishing finalized post-quantum standards.While experts debate whether quantum threats will materialize in five or fifty years, Aptos is choosing conservative preparation over reactive scrambling. Plans for a post-quantum future on Aptos, drafted by @AptosLabs' Head of Cryptography, @alinush.â†' AIP-137 aims to empower Aptos to better respond to future developments in quantum computing with a focus on ease of integration & limited new security assumptions.Learn more https://t.co/dgPRueL4Jk- Aptos (@Aptos) December 18, 2025 Conservative Security Over PerformanceAIP-137 prioritizes security assumptions over efficiency by selecting SLH-DSA-SHA2-128s, a stateless hash-based signature scheme standardized by NIST as FIPS 205.The scheme relies exclusively on SHA-256, a hash function already embedded throughout Aptos infrastructure, requiring no new cryptographic assumptions.This conservative approach addresses past failures in post-quantum cryptography, where schemes like Rainbow, a NIST finalist based on multivariate cryptography, were broken entirely on commodity laptops in 2022.By building on proven hash functions rather than exotic mathematical assumptions, Aptos minimizes the risk of classical attacks defeating supposedly quantum-secure schemes.The trade-off is between size and speed. Signatures will measure 7,856 bytes, 82 times larger than Ed25519, while verification takes approximately 294 microseconds, roughly 4.8 times slower.These performance costs are deliberate, accepting efficiency losses in exchange for ironclad security guarantees that don't introduce untested cryptographic assumptions into the system.Alternative schemes like ML-DSA offer smaller signatures and faster verification but depend on the hardness of structured lattice problems, introducing new mathematical assumptions.Falcon delivers even better performance with compressed signatures around 1.5 KB, but requires floating-point arithmetic, which makes implementation error-prone.Aptos is reserving these aggressive optimizations for future proposals once SLH-DSA establishes a conservative baseline.Preparing Without Mandating MigrationThe proposal explicitly avoids forced migration, keeping Ed25519 as the default signature scheme while introducing SLH-DSA as an optional layer that governance can enable when quantum threats warrant activation.Users requiring post-quantum assurances can adopt the scheme selectively without disrupting the broader network.This measured approach aligns with broader industry perspectives on quantum preparedness. MicroStrategy founder Michael Saylor recently argued that "quantum computing won't break BitcoinâEUR"it will harden it," suggesting that networks that upgrade proactively will see security improve while supply dynamics tighten, as lost coins remain frozen. The Bitcoin Quantum Leap: Quantum computing wonâEUR(TM)t break BitcoinâEUR"it will harden it. The network upgrades, active coins migrate, lost coins stay frozen. Security goes up. Supply comes down. Bitcoin grows stronger.- Michael Saylor (@saylor) December 16, 2025 His view reflects a growing consensus that quantum threats, while serious, present opportunities for networks prepared to evolve their cryptographic foundations.For Aptos, implementation includes feature flags allowing controlled deployment across validators, indexers, wallets, and development tools. The phased rollout gives the ecosystem time to adapt infrastructure before quantum computers become capable of breaking current cryptography.Industry-Wide Quantum Concerns MountThe proposal reflects broader anxiety in the crypto industry about the timelines for quantum computing. Solana co-founder Anatoly Yakovenko recently warned that Bitcoin has a 50% chance of facing quantum breakthroughs within five years, urging...