Coinkite Coldcard Mk4

Dual Secure Element for Key Storage

We find it quite scary that some hardware wallets trust the main microprocessor with their most valuable secrets. Instead, COLDCARD uses two Secure Elements, from different vendors, to protect your Bitcoin.

Specifically, the COLDCARD uses Microchip's ATECC608 and Maxim's DS28C36B, to store the critical master secret: the 24-word seed phrase for your BIP39 wallet.

For your funds to be compromised, a backdoor would need to exist for 3 different chips: both the Secure Elements, and the main microprocessor.