Zcash founder Zooko Wilcox announced that an AI-assisted security audit found no new serious vulnerabilities in the privacy-focused cryptocurrency's protocol after developers fixed a previously discovered Orchard bug. The audit was commissioned by Shielded Labs, a Swiss non-profit foundation supporting Zcash development, and used Anthropic's Claude Mythos model to review the protocol. The assessment followed a June 3 incident when developers temporarily paused transactions in the Orchard shielded pool after discovering a design vulnerability, with functionality restored later the same day through an emergency upgrade.
Shielded Labs Commissions AI Audit Using Claude Mythos
Shielded Labs commissioned the security audit after the Orchard bug fix. According to Wilcox, Anthropic's Claude Mythos model reviewed the Zcash protocol and did not identify any additional serious flaws. The audit aimed to verify protocol integrity following the vulnerability remediation.
Developers Paused Orchard Pool on June 3, Restored Same Day
On June 3, developers temporarily paused transactions in the Orchard shielded pool after discovering a vulnerability in its design. Functionality was restored later the same day through an emergency upgrade. The bug had reportedly existed for about four years and was discovered by security researcher Taylor Hornby with assistance from Anthropic's Claude Opus 4.8 model. The Zcash Foundation said it found no evidence that the flaw had been exploited, no signs of unauthorized ZEC creation, and no indication that users' private data had been exposed. Zcash price began to recover after plunging more than 45% in early June.
AI Models Expand Role in Crypto Security Auditing
Advanced AI models are increasingly being used to search for flaws in complex protocols, smart contracts, and cryptographic systems that are difficult for humans to review manually. The Zcash case demonstrates AI's application in identifying vulnerabilities in zero-knowledge proof systems, which are mathematically complex and depend on subtle constraints that can be extremely difficult to verify through traditional review.
US Regulators Suspend Access to Anthropic Models
Anthropic released Claude Fable 5, a public version connected to its Mythos-class security research models. The launch followed claims that Mythos had identified thousands of high- and critical-severity vulnerabilities in systemically important software. Fable 5 included safety mechanisms, with some requests involving high-risk areas redirected to Claude Opus 4.8. Shortly after release, access to Fable 5 and Mythos 5 was suspended following pressure from US export-control regulators, who cited national security concerns.
Shielded Labs Proposes Turnstile Mechanism for Supply Verification
Because Orchard is private by design, it is difficult to retrospectively audit the full ZEC supply over the period when the bug existed. Shielded Labs is working on a proposal for a "turnstile" mechanism that would help verify the integrity of the coin supply. This mechanism aims to address structural uncertainty in systems where privacy prevents full historical visibility.
FAQ
What did Zcash developers do on June 3?
On June 3, Zcash developers temporarily paused transactions in the Orchard shielded pool after discovering a design vulnerability, then restored functionality later the same day through an emergency upgrade.
Why did US regulators suspend access to Anthropic's AI models?
US export-control regulators suspended access to Claude Fable 5 and Mythos 5 shortly after release, citing national security concerns related to the models' ability to identify thousands of high- and critical-severity vulnerabilities in systemically important software.
How long did the Orchard bug exist before discovery?
The Orchard bug had reportedly existed for about four years before security researcher Taylor Hornby discovered it with assistance from Anthropic's Claude Opus 4.8 model.
