The devices, beyond the product sheet

An ST33 with a vendor OS (BOLOS): keys are born and sign inside the chip. This is not an authenticator, and Recover is possible only because Ledger can program the silicon.

Open MCU firmware, reproducible builds, OPTIGA Trust M as a companion SE — not as the wallet CPU. Heir to the Trezors without helper silicon.

TROPIC01 is a RISC-V with published RTL, hence programmable. OPTIGA and the STM32U5 are there so that this layer alone does not pay the seed. Auditable is not “the die equals the Verilog”.

Two fixed-instruction authenticators (ATECC608 + DS28C36B), not two ST33s. The open MCU is the wallet. Bitcoin-only, air-gap — and, in 2026, the harshest reminder about entropy.

Swiss, open firmware, Bitcoin-only edition available. A sober hybrid, without marketing theater.

Libre firmware, hardware schematics under CERN-OHL, e-ink, QR air-gap, Bitcoin-only. The top of the transparency scale.

QR air-gap, large screen, several chips, multi-coin. A signing lab that does not plug in.

Open source, inexpensive, QR air-gap possible, Bitcoin and Liquid. The honest entry into verifiable self-custody.

Open firmware, SE, multi-coin, touchscreen on Pro. The Asian alternative to the Trezor / Ledger hybrid.

NFC card, seedless by default: the key is born inside a Samsung EAL6+ SE and never leaves it. The backup is other identical cards.

A real JavaCard (NXP JCOP + AGPLv3 applet), not an ATECC and not a Tangem. The applet can be read; the card OS cannot.

Stateless, open source, QR, dice. The device is no longer a vault: it is a calculator emptied at every shutdown.

The firmware, not the case. Krux turns Kendryte K210 vision modules into Bitcoin signers. Yahboom is the no-solder path.

A ~$45 vision sensor, not a Bitcoin product. Flash Krux in minutes: air-gapped signer, touchscreen, camera, no Wi-Fi, no soldering.

Metal air-gap, battery, camera, multi-coin. Isolation from the PC without going through DIY.