BitBox02

BitBox02 is a hardware wallet developed and manufactured by Shift Crypto, a company based in Switzerland. It stores private keys and signs transactions on a dedicated device that connects to a host computer or phone over USB-C, with on-device confirmation of addresses and amounts before anything is signed. It ships in two editions: a Bitcoin-only edition, which carries less firmware code by excluding all other assets, and a multi-asset edition that additionally supports other networks and tokens.

Security architecture

The BitBox02 pairs a general-purpose microcontroller with a dedicated secure chip used to harden key protection against physical extraction. The design is candid about the trade-off every wallet maker faces: fully open general-purpose silicon is auditable but physically softer, while conventional secure elements are hardened but closed. Shift Crypto's approach keeps the wallet logic on the open microcontroller and uses the secure chip to strengthen it — additional key-stretching and monotonic counters that make brute-forcing the device PIN impractical — rather than placing all trust in a closed chip. The firmware is open source and supports reproducible builds, so an independent reviewer can rebuild it from source and confirm the result matches the released image; the companion-app code is published as well.

Interface and backup

Rather than physical buttons, the BitBox02 uses capacitive touch sliders along the edges of the device for navigation, with gestures to confirm or reject. Its most distinctive convenience feature is backup to a bundled microSD card: the wallet can write an encrypted backup of the seed at setup, in addition to (or alongside) the conventional written seed phrase. That lowers the barrier for newcomers who might otherwise postpone making any backup at all, though a card stored next to the device protects against device failure, not house fire — a durable offsite or steel seed backup remains best practice. Optional BIP-39 passphrases add a hidden-wallet layer for users who want it.

Workflow and compatibility

The device pairs with the BitBoxApp on desktop and mobile for sending, receiving, and coin management, and the app can connect to the user's own full node for verification rather than Shift's servers — the detail that separates private self-custody from custody that still leaks addresses to a vendor. It also works with third-party coordinators such as Sparrow and Specter Desktop over the PSBT standard, including service as a cosigner in multisig setups.

Where it fits

A few operational habits get the most out of the device. Verify every receive address on the BitBox02's own screen rather than trusting the host display — the entire point of dedicated-screen hardware is that malware on the computer cannot forge what the device shows. Test the microSD backup by actually restoring it, on a spare device or after a deliberate reset, before the wallet holds meaningful funds; an untested backup is a hypothesis, not a safety net. If you adopt a passphrase, treat it as a second secret with its own durable backup, because no manufacturer can recover a forgotten passphrase and the standard seed alone will open only the unhidden wallet. And source the device from the manufacturer or authorized channels — the BitBox02's attestation check verifies genuine hardware at setup, but shrinking the supply-chain window remains cheap insurance. These habits are device-agnostic, which is rather the point: good custody is mostly procedure, with hardware as the enforcement layer.

The BitBox02 occupies the pragmatic middle of the hardware-wallet spectrum: connected rather than air-gapped, but open, reproducible, and node-friendly. For users who want signing verified on dedicated hardware without the ceremony of QR codes and SD-card shuttling, it is a defensible choice; those with higher threat models may prefer fully air-gapped signers. See hardware wallet and cold storage for the surrounding concepts.