Ledger chief technology officer Charles Guillemet is telling Bitcoin users to pump the brakes on multisignature wallets — at least for now. His warning comes on the heels of a security incident involving Coldcard, a popular hardware wallet maker. Guillemet's message: multisig isn't a magic bullet, and adopting it without understanding the trade-offs can backfire.
What multisig is — and isn't
Multisignature setups require multiple private keys to authorize a transaction. They're often pitched as a way to spread risk: if one key is compromised, the funds stay safe. But Guillemet argues that the added complexity can create new attack surfaces. A poorly configured multisig wallet, he says, might actually be less secure than a well-managed single-key setup.
The Coldcard trigger
Coldcard disclosed a vulnerability this month that affected certain firmware versions. The company patched it quickly, but the incident rattled some users. Guillemet pointed to the episode as a reminder that no hardware is infallible — and that layering on extra keys without understanding the underlying security model can lead to mistakes.
What Guillemet wants users to do instead
The CTO isn't anti-multisig. He's anti-rush. His advice: stick with a single, well-audited hardware wallet for now. If you do want to explore multisig, test it with small amounts first. Understand the recovery path. Know what happens if one device fails. The goal, he says, is to avoid a false sense of security.
Industry reaction
No major figures have publicly pushed back on Guillemet's comments, but the debate is familiar. Multisig advocates argue that the learning curve is worth it for high-value holdings. Critics say the average user is better off with a simpler setup. The Coldcard incident has given both sides fresh ammunition.
For now, Guillemet's message is clear: don't let a single security scare push you into a solution you don't fully grasp. The next concrete step? Ledger is expected to release updated guidance on multisig best practices in the coming weeks.
