Coinkite
Coinkite is a Canadian bitcoin hardware company best known for COLDCARD hardware wallets and OPENDIME bearer devices. It sells bitcoin-focused security products and is not an exchange or mixing service.[1]
COLDCARD seed-generation advisory (2026)
In 2026 Coinkite published a security advisory describing a firmware bug that weakened device-generated seed entropy on affected COLDCARD releases. The company stated the devices were not remotely compromised; attackers regenerated weak seeds offline. Fixed firmware tracks include Mk4/Mk5 standard 5.6.x (and later hotfix 5.6.1) and Q standard 1.5.xQ (hotfix 1.5.1Q), with separate Edge tracks and older Mk2/Mk3 fixes documented on Coinkite’s advisory pages.[2][3][4]
Updating firmware does not repair an already-generated weak seed; Coinkite’s guidance is to install fixed firmware and migrate funds to a newly generated seed when the advisory applies. TAPSIGNER, OPENDIME, and SATSCARD were described as unaffected because they use different codebases.[2]