AI Auditor Targets Monero After Uncovering Critical Zcash Bug

Security researcher Taylor Hornby plans to add Monero (XMR) to his cryptocurrency audit queue after successfully using Anthropic’s Claude Opus 4.8 AI model to uncover a critical vulnerability in Zcash (ZEC). The discovery highlighted the growing role of artificial intelligence in blockchain security and privacy coin audits.

Hornby confirmed his intention to investigate Monero and other privacy-focused cryptocurrencies after revealing a severe flaw in Zcash that briefly shook investor confidence. Following public disclosure of the issue, ZEC lost roughly 30% of its value before developers released an emergency patch to secure the network.

The vulnerability was discovered during an audit commissioned by nonprofit development organization Shielded Labs in April. On May 29, Hornby deployed a custom security auditing agent powered by Claude Opus 4.8. Within 24 hours, the AI-assisted review identified a soundness flaw in Zcash’s Orchard shielded pool, making it one of the first major security breakthroughs attributed to the newly released model.

According to Hornby, the bug stemmed from an under-constrained elliptic curve validation check that had existed since Orchard launched in May 2022. If exploited, the flaw could have allowed attackers to create unlimited counterfeit ZEC tokens within the shielded pool without detection. Developers successfully patched the issue on June 2. While Shielded Labs stated there is no evidence the vulnerability was exploited, it acknowledged that cryptographic certainty is impossible in this case.

Attention is now turning to Monero, the largest privacy-focused cryptocurrency with mandatory transaction privacy. Unlike Zcash, which offers optional shielding, Monero conceals transaction details by default. Recent Monero network upgrades have expanded its privacy capabilities, potentially creating new areas for security researchers to examine.

Hornby also indicated that additional privacy coin projects may be reviewed in the future, depending on available funding. He plans to seek support through a Zcash coinholder grant program to continue his research.

Following the patch, Zcash recovered much of its losses and traded near $373, while Monero declined nearly 10% to around $299. The incident has also intensified efforts toward formal verification in cryptocurrency development, including initiatives backed by the Winklevoss twins.

The episode demonstrates how advanced AI tools are becoming valuable assets in cybersecurity, helping researchers identify vulnerabilities that traditional audits and human reviewers may overlook for years.