Security engineer Taylor Hornby, who recently used Anthropic’s Opus 4.8 AI model to uncover a critical vulnerability in Zcash, has announced plans to audit the privacy coin Monero next.
Hornby responded on X to a query about whether he would examine Monero and similar private cryptocurrencies. He wrote, “Absolutely! I’ll add Monero to my queue of things to audit.”
Monero, trading under the ticker XMR, is one of the largest privacy-focused cryptocurrencies. Unlike Zcash, where users can choose between transparent or shielded addresses, Monero hides transaction details by default.
The Zcash Bug Discovery
The Zcash flaw was found on May 29 by Hornby, who was hired by Shielded Labs in April specifically to find protocol bugs before attackers could. The vulnerability, located in the blockchain’s Orchard privacy pool, had remained undetected since May 2022. It could have allowed an attacker to mint unlimited, undetectable counterfeit ZEC tokens.
Shielded Labs, a nonprofit developer on the network, disclosed the bug on Thursday and pushed through an emergency fix by June 1.
Market Reaction and Fallout
Following the disclosure, Zcash’s token price fell 38% within 24 hours. Concerns arose that a hacker might have already exploited the shielded pool vulnerability, potentially stealing funds without leaving any detectable trace over the past few years.
Hornby explained that he reported the bug rather than exploiting it because the Zcash developers were “like family” to him. He said he could “not live with that kind of betrayal.” He plans to apply for a Zcash coinholder grant to fund further work.
Monero’s Turn in the Spotlight
Hornby’s decision to audit Monero next signals a growing interest in hardening privacy coins against subtle protocol flaws. Given that Monero’s privacy model is more aggressive than Zcash’s, any vulnerabilities found could have significant implications.
It remains unclear when exactly Hornby will begin the Monero audit. He has not specified a timeline, but his track record suggests he will approach it with the same thoroughness—and perhaps the same AI tools—that found the Zcash bug.
For now, the community watches closely. The intersection of AI-assisted security audits and privacy-focused blockchains appears to be an emerging battleground. And Hornby seems willing to lead the charge.
