Coldcard Mk4

Coldcard Mk4 uses two certified secure element chips from separate manufacturers — an ATECC608B and a DS28C36B — so neither chip alone can access the private key material. All firmware is fully open source and auditable on GitHub. The device supports fully air-gapped operation via microSD and NFC. No supply chain compromises or confirmed security breaches have been publicly reported.

Coldcard Mk4 is the only mainstream hardware wallet to use two independent secure element chips from separate manufacturers, reducing single-vendor supply chain risk. It offers coercion-resistant PIN options including a duress PIN that opens a decoy wallet and a brick-me PIN that permanently destroys the secure elements. The onboard keyboard means seed words and PINs are never entered on a connected computer.

No. Coldcard Mk4 is Bitcoin-only and does not support Ethereum, Solana, or altcoins. This is a deliberate design choice by Coinkite — a narrower firmware scope means a smaller, more auditable codebase and fewer edge cases introduced by multi-coin support. Users who need multi-chain coverage should consider a different hardware wallet.

No publicly confirmed security incidents, critical firmware vulnerabilities, or supply chain compromises have been disclosed for any Coldcard model. Coinkite publishes a public firmware changelog and all releases are signed and verified on-device at boot. Multiple independent security researchers have reviewed the open-source firmware without reporting unpatched critical issues.

Coinkite ships Coldcard devices with tamper-evident packaging, and the device performs a cryptographic self-check at first boot to verify the firmware has not been modified since manufacture. Coinkite maintains a list of authorised resellers on its website. Purchasing from an unverified third party carries additional supply chain risk that these checks help mitigate but cannot fully eliminate.