Trezor

Our assessment

Trezor is the only device in this comparison that passed every indicator we checked. Its firmware source is public, its security and specification pages are reachable, its documentation needs no account, and — unusually for this category — its legal terms are published at a conventional address. On what an outsider can verify before buying, nothing here beats it.

Open firmware is the whole argument

The Safe range pairs an EAL6+ secure element with firmware that stays fully open source, so the secure element guards the PIN and the entropy while the logic that builds and signs transactions remains auditable by anyone. That split is a deliberate design position, and it is the opposite of the approach taken by devices whose secure-element operating system is closed.

What our score does and does not measure

This rubric scores verifiable openness, not physical security. We do not test tamper resistance, we do not attempt side-channel attacks, and we do not score marketing claims about chip certification. What we can check is whether the code, the specifications, the documentation and the legal terms are published where a buyer can read them before paying — and here they all are.

The gap that remains

Several questions in this category cannot be settled from a browser: supply-chain integrity, how the device behaves in an adversary's hands, the response to a future firmware vulnerability. Trezor's own history includes a physical extraction demonstrated by researchers on older models, which is exactly the kind of finding that open hardware makes public rather than hides.

Who it suits

Trezor fits buyers who want the maximum amount of independently checkable evidence and are comfortable with a device that publishes its weaknesses along with its strengths. Buyers who want a Bitcoin-only attack surface should look at Coldcard, BitBox or Foundation Passport instead.