Former Mt. Gox CEO Mark Karpelès has criticized Ledger’s response to a hardware wallet supply chain attack involving sophisticated implants, arguing that the company should have issued a stronger public warning after documenting advanced implant designs in March 2026. Supply chain attacks of this kind involve tampering with devices before they reach buyers, which is why guidance around purchase channels carries particular weight in hardware wallet security.

Karpelès says clearer communication could have prevented more than $90 million in losses. Those figures and assessments reflect Karpelès’ public statements; the supplied information does not independently establish the amount of losses attributable to alleged communication failures.

Ledger CEO Pascal Gauthier responded by referencing Karpelès’ history leading Mt. Gox. The exchange has raised questions about how hardware wallet providers communicate emerging security threats to customers.

Ledger’s March Disclosure

Karpelès acknowledged that Ledger published an educational article about the implant threat through Ledger Academy in March 2026. The article reportedly recommended purchasing devices directly from Ledger or its authorized resellers.

However, Karpelès argued that a single educational article was insufficient for a threat of this severity. In his view, evidence of mass-produced, self-aligning implants should have prompted an urgent security response.

He pointed to multiple reports of implants received in early 2026 and referenced hardware implant designs documented by security researcher Joe Grand, including a handmade device fitted with an improvised LTE antenna. According to Karpelès, Ledger’s March article showed both the handmade style of implant described by Grand and more advanced, mass-produced designs.

Karpelès said the devices indicated a serious effort to compromise Ledger products and described the situation as a potential “five-alarm fire” requiring immediate and appropriate action. He also estimated that better communication at the time could have prevented more than $90 million in losses.

In a post on X dated October 17, 2026, Karpelès wrote:

I'm not sure MtGox has anything to do with that. You received multiple reports of implants in early 2026, and by March you published an article that showed both the hand-made style of implants Joe Grand saw (with the improvised LTE antenna) and the high budget mass produced… — Mark Karpelès (@MagicalTux) October 17, 2026

Dispute Over Ledger’s Response

The dispute intensified after Gauthier invoked Karpelès’ history as Mt. Gox CEO. Mt. Gox, once the world’s largest bitcoin exchange, collapsed in 2014 after losing hundreds of thousands of bitcoins to hackers. Karpelès rejected that criticism, arguing that the exchange’s past had no bearing on Ledger’s responsibilities. He said he had expected Ledger to learn from Mt. Gox’s failures and maintain stronger security and disclosure standards.

Karpelès also questioned Ledger’s continued characterization of the incident as the CryptoBilis incident. He noted that similar implants had reportedly surfaced in other locations. While acknowledging that Ledger might have reasons for its terminology, he argued that customers should not have to determine whether their devices had been altered.

He recognized some improvements, including greater involvement from Ledger’s X account, but said users continued to report difficulties obtaining responses from the company.

The controversy highlights a distinction in hardware wallet security: publishing technical guidance is not necessarily equivalent to issuing an urgent customer warning. Users need clear information about potential threats, recommended purchasing channels, and steps to assess their exposure. How providers escalate such findings to customers beyond publishing educational content remains a central question in the dispute.

Hardware wallets protect private keys by keeping them isolated from ordinary internet-connected environments. However, compromised hardware can undermine those protections if malicious components interfere with device operations or security checks.

The dispute has renewed attention on the importance of purchasing hardware wallets directly from manufacturers or authorized resellers, as well as the role of transparent incident reporting when sophisticated attacks threaten devices designed to protect digital assets.