Aptos Introduces Quantum-Resistant Signatures to Enhance Blockchain Security

Summary:
Aptos has announced the introduction of AIP-137, featuring SLH-DSA-SHA2-128s, as its first quantum-resistant signature scheme. This initiative seeks to bolster the network's defenses against potential quantum computing threats while maintaining the existing default signature scheme, Ed25519.

Key Takeaways

Aptos has proposed AIP-137, introducing a post-quantum signature scheme called SLH-DSA-SHA2-128s.
The design prioritizes security over efficiency, employing the SHA-256 hash function to avoid new cryptographic assumptions.
Users can adopt this new signature scheme without mandating a network-wide migration.
The proposal underscores the growing concern in the crypto industry regarding quantum computing threats.
Major technology companies are rapidly advancing their quantum computing capabilities, heightening the need for blockchain upgrades.

Aptos Introduces Quantum-Resistant Signatures to Enhance Blockchain Security

Introduction to AIP-137

Aptos has revealed AIP-137, presenting SLH-DSA-SHA2-128s as its inaugural signature scheme resistant to quantum computing, aiming to safeguard against future cryptographic threats.

This initiative was drafted by Alin Tomescu, Aptos Labs Head of Cryptography. It seeks to proactively prepare the network for the arrival of quantum computers that could impact cryptography before they become a significant risk.

As quantum computing evolves from a theoretical notion to a reality—with IBM exploring scaling strategies and NIST releasing finalized post-quantum standards—Aptos is adopting a forward-thinking strategy rather than a reactive one.

Prioritizing Security Over Speed

Conservative Security Approach

AIP-137 emphasizes security by opting for SLH-DSA-SHA2-128s, a stateless hash-based signature scheme recognized by NIST as FIPS 205. This scheme uses SHA-256, a hash function already integrated into the Aptos network, which reduces the need for new cryptographic principles.

This cautious strategy addresses previous shortcomings in post-quantum cryptography, where schemes like Rainbow—a NIST finalist based on multivariate cryptography—were fully compromised using standard laptops in 2022.

By operating on established hash functions instead of experimental mathematical ideas, Aptos lowers the likelihood of conventional attacks undermining supposedly quantum-secure solutions.

The trade-off involves signature size and speed: signatures will be 7,856 bytes—82 times larger than Ed25519—while verification will take around 294 microseconds, making it approximately 4.8 times slower.

These performance costs are a deliberate choice, favoring reliability and security assurances over efficiency by avoiding untested cryptographic principles.

Alternative systems like ML-DSA offer smaller signatures and quicker verification times, but they depend on the complexity of structured lattice issues, introducing new mathematical premises.

Falcon provides even better performance with compact signatures of about 1.5 KB; however, it requires floating-point arithmetic, which increases the risk of implementation errors.

Aptos plans to hold off on these more aggressive optimizations for future proposals until SLH-DSA establishes a reliable baseline.

Future-Proofing Without Pressure to Transition

User Flexibility

The proposal intentionally avoids necessitating a migration, keeping Ed25519 as the default signature scheme. Users can opt into the SLH-DSA when needed without disrupting the broader network.

This thoughtful approach aligns well with industry-wide discussions regarding readiness for quantum technology.

MicroStrategy’s founder, Michael Saylor, recently claimed, “quantum computing won’t break Bitcoin—it will harden it.” This notion posits that networks that proactively adapt will strengthen their security while tightening supply dynamics, as lost coins remain inaccessible.

For Aptos, the implementation of the new scheme includes feature flags to allow controlled deployment across validators, indexers, wallets, and development tools.

This phased rollout offers the ecosystem ample time to adjust its infrastructure before quantum computers reach a capacity capable of breaching current cryptographic systems.

Growing Concerns About Quantum Threats

Industry-Wide Implications

This proposal reflects escalating worry within the crypto sector regarding the timelines for quantum computing advancements.

Solana co-founder Anatoly Yakovenko has voiced concerns, asserting that Bitcoin faces a 50% chance of encountering quantum breakthroughs within five years. He advocates for a swift transition to quantum-resistant schemes, particularly as AI advances quicken development.

Experts estimate that approximately 30% of Bitcoin’s supply—around 6-7 million BTC, worth hundreds of billions of dollars—remains vulnerable in older address formats, as these formats expose public keys directly.

Tech Giants are rushing toward quantum supremacy with ambitious timelines. IBM aims to develop 100,000-qubit chipsets by the end of this decade, while PsiQuantum seeks to achieve one million photonic qubits in the same period.

Microsoft has remarked that quantum computing is now “years, not decades” away, supported by recent chip advancements, while Google's Willow chip accomplished tasks in five minutes that would take classical computers billions of years.

Gavin Brennen from Macquarie University stated that projections for breaking 256-bit elliptic curve signatures have plummeted from 10-20 million qubits to about one million, implying that “a plausible timeline for cracking 256-bit digital signatures is by the mid-2030s.”

Grayscale’s 2026 Digital Asset Outlook also recognized quantum computing as a long-term cryptographic challenge but downplayed immediate price impacts, noting that cryptographically relevant quantum computers are unlikely to emerge before 2030.

However, the asset manager stressed that as technology approaches practical feasibility, most blockchains will ultimately need to implement post-quantum upgrades.