Wallet dossier
COLDCARD
Bitcoin-only self-custody hardware signing-device family made by Coinkite, with multiple Mk generations and the Q model.
- Developer / company
- Coinkite Inc.
- Origin
- —
- Launch
- 2017
- Custody
- self_custody
- Confidence
- high
- Last verified
- 2026-08-14
Product family
Products
COLDCARD Mk2 Bitcoin-only hardware signing device in the COLDCARD lineage.
COLDCARD Mk3 Bitcoin-only hardware signing device in the COLDCARD lineage.
COLDCARD Mk4 Bitcoin-only hardware signing device in the COLDCARD lineage.
COLDCARD Mk5 Bitcoin-only hardware signing device in the COLDCARD lineage.
COLDCARD Q Bitcoin-only hardware signing device in the COLDCARD lineage.
Chronology
Lifecycle timeline
COLDCARD Mk3 released in 2019
Product: COLDCARD Mk3
Coinkite's first-party production and retrospective sales history establishes that COLDCARD Mk3 entered the released/sold product lineage during 2019.
COLDCARD Mk2 released in 2019
Product: COLDCARD Mk2
Coinkite first-party product history and official firmware hardware support establish the mechanical-key COLDCARD Mk2 lineage during 2019.
COLDCARD Mk2 publicly described with new hardware and firmware changes
Product: COLDCARD Mk2
Coinkite publicly described the new COLDCARD Mk2, including mechanical buttons and hardware and firmware changes intended to harden the device against PIN-bypass attacks.
COLDCARD Mk3 announced and first-batch preorders opened
Product: COLDCARD Mk3
Coinkite announced COLDCARD Mark 3, opened first-batch preorders, and stated that units were planned to ship by October 2019.
COLDCARD Mk4 introduced
Product: COLDCARD Mk4
COLDCARD documentation records the Mk4 generation as introduced in 2022.
Seed-generation entropy defect disclosed
COLDCARD disclosed a seed-generation defect in affected firmware lines. Fixed releases restore the intended hardware-randomness path for future seed generation, but existing affected seeds require migration unless an advisory exception applies.
Fixed COLDCARD firmware released across supported model lines
Coinkite released fixed firmware for the supported COLDCARD model and track matrix and published migration guidance for existing affected seeds.
Sources