SeedSigner
Open-source, DIY Bitcoin signing device built from commodity hardware. Designed for air-gapped seed generation, transaction signing, and multisig coordination without trusting proprietary hardware.
Open-source, DIY Bitcoin signing device built from commodity hardware. Designed for air-gapped seed generation, transaction signing, and multisig coordination without trusting proprietary hardware.
NFC-enabled card from Coinkite storing a Bitcoin private key. Sign transactions by tapping the card to your phone.