Ledger's own security documentation now states that its Genuine Check feature cannot detect spying implants that leave the secure chip intact. The admission matters because Genuine Check is the tool buyers are pointed to when they want to know whether a device they've bought secondhand, or from a reseller, is legitimate. If the chip is untouched, the check passes — even if something else on the board has been added.
The limitation surfaced again this week after Pascal Karpelès flagged another Ledger implant incident. Karpelès, a longtime hardware-wallet critic, has now raised the issue more than once. Ledger, for its part, continues to maintain its CryptoBilis warning — a notice about a reseller the company has previously flagged.
The chip is the only thing Genuine Check reads
Genuine Check works by asking a Ledger device to prove it holds a genuine secure element. That's the chip that stores private keys. If an attacker adds components around the chip — a small radio, a microcontroller, something that intercepts data before it reaches the secure element — the chip itself still answers correctly. The check returns a pass.
This isn't a flaw in the cryptography. It's a scope problem. Ledger's documentation is explicit that the feature is not designed to catch physical tampering that leaves the chip intact. The company's position is that Genuine Check verifies the chip, not the whole device.
For anyone buying a Ledger from a third party, that distinction is the whole ballgame. A sealed box and a passing Genuine Check don't prove the device is clean.
Why Karpelès keeps coming back to this
Karpelès has flagged implant incidents before, and his latest post points to the same structural gap. His argument, stripped down: a verification tool that only inspects one component gives buyers a false sense of coverage. The implant doesn't need to touch the chip to do its job.
Ledger hasn't disputed the technical description in its own documentation. The company has instead kept its CryptoBilis warning live, which suggests it sees the reseller channel as an ongoing concern rather than a closed incident.
Not just a CryptoBilis problem
The limitation applies to any Ledger bought from any reseller. Genuine Check doesn't know where a device came from. It only knows whether the secure chip answers correctly. That means the blind spot is a property of the feature itself, not of one bad actor.
Buyers who've been told to "just run Genuine Check" are getting incomplete advice. The check is necessary. It isn't sufficient.
Ledger hasn't said whether it plans to expand what Genuine Check inspects, and the company hasn't announced a new physical-tamper detection feature. Until that changes, the only reliable way to avoid an implanted device is to buy directly from Ledger or from a reseller you'd trust with your seed phrase. Which is a short list.
