AI Breaks HAWK Signature Scheme — The End of Classical Cryptographic Security?

Anthropic's Claude Mythos Preview model recently broke a proposed digital signature algorithm in just 60 hours (CoinDesk, June 2024). The attack halved the effective key strength of HAWK, a primary candidate for next-generation cryptographic security.

AI-Driven Attacks Halve HAWK Security in 60 Hours

The discovery by Anthropic represents a massive leap in the speed of cryptographic exploitation (CoinDesk, June 2024). Against HAWK’s smallest parameter set, the AI reduced the expected computational cost of recovering a key from 2^64 operations to 2^38 (CoinDesk, June 2024). This reduction marks a significant degradation in security, even if larger keys remain currently impractical to attack.

The attack was achieved using roughly $100,000 in computing costs (CoinDesk, June 2024). This efficiency is striking because the HAWK algorithm had previously survived two years of rigorous expert human review (CoinDesk, June 2024). The ability of a model to bypass human-vetted defenses in a matter of days suggests a fundamental shift in the threat landscape.

Anthropic disclosed the vulnerability to the authors of HAWK in June 2024 (CoinDesk, June 2024). The company coordinated the publication with the NIST (National Institute of Standards and Technology) public mailing list to ensure the industry could respond. This proactive disclosure highlights a new era where AI models serve as high-speed stress testers for global security protocols.

The Migration Window for Bitcoin and Ether Closes Faster

The speed of these classical attacks is increasing by up to 20-fold (BIP-361, 2024). This acceleration directly impacts the urgency of BIP-361, a proposal designed to freeze more than a third of the total Bitcoin supply (BIP-361, 2024). The proposal argues that the window for migrating to quantum-resistant addresses is closing much faster than previously estimated.

Current digital signature schemes, which use elliptic curve signatures, are expected to fail entirely when faced with quantum computers (CoinDesk, June 2024). While the recent Anthropic attack did not target the specific elliptic curve signatures used by Bitcoin or Ether, the trend is clear. The vulnerability of classical algorithms to AI-driven optimization is a precursor to the quantum threat.

Bitcoin has already drafted contingency plans through BIP-360 (CoinDesk, June 2024). This proposal specifies three algorithms already standardized by NIST (National Institute of Standards and Technology) to provide quantum-resistant addresses. By including multiple algorithms, the protocol aims to provide fallbacks if one specific method is broken by classical or quantum advances.

AI Targets Encryption and Privacy Protocols

The threat extends beyond digital signatures to the fundamental encryption used to secure data. Anthropic reported a second result that improved attacks on a weakened version of AES (Advanced Encryption Standard) by factors of 200 to 800 (CoinDesk, June 2024). AES is the industry-standard cipher used to encrypt everything from web traffic to local wallet files.

For developers of privacy-centric protocols, the news is a mixed bag of caution and relative stability. Anthropic reported that the model produced smaller improvements—under tenfold—against Poseidon (CoinDesk, June 2024). Poseidon is the specific hash function (a mathematical function that turns an input into a fixed-size string of characters) that underpins many zero-knowledge proof systems (CoinDesk, June 2024).

These zero-knowledge proofs are critical for securing rollups (Layer 2 scaling solutions that bundle transactions) and privacy protocols (CoinDesk, June 2024). While Poseidon remains more resilient than HAWK or AES, the fact that an AI can find improvements in under tenfold efficiency is a signal to the industry. The speed of discovery is no longer limited by human cognitive capacity.

Privacy Networks Accelerate Quantum Defense Upgrades

The timing of these AI breakthroughs coincides with critical shifts in on-chain privacy infrastructure. Zcash activated a major upgrade on Tuesday (CoinDesk, June 2024). This upgrade introduced a new shielded pool (a privacy-preserving transaction layer) designed to remain recoverable even if quantum computers become available (CoinDesk, June 2024).

This proactive move highlights the industry's realization that the transition to post-quantum cryptography (PQC) cannot wait for the arrival of a large-scale quantum computer. The threat is already manifesting through classical AI-driven optimizations that weaken existing standards. Protocols are now forced to defend against two fronts: the eventual quantum threat and the immediate AI-driven classical threat.

The race is no longer just between humans and machines, but between the speed of AI-driven cryptanalysis and the speed of protocol upgrades. As AI models like Claude demonstrate the ability to find vulnerabilities in hours rather than years, the standard for 'ecure' is being recalculated in real-time. The industry must now outpace the machine to maintain the integrity of digital assets.

Key Developments to Watch

• NIST Post-Quantum Standards (by late 2025) — the finalization of these standards will dictate the migration path for most global financial systems.
• Zcash Network (ongoing) — the performance and security of the new shielded pool will serve as a test case for quantum-resilience in live environments.
• BIP-361 Implementation (by 2026) — the debate over freezing a third of Bitcoin's supply will determine the protocol's approach to rapid cryptographic migration.

As AI models reduce the cost of cryptographic attacks from years to hours, is the concept of 'athematical certainty' in security becoming obsolete?