COLD BOY v0.1

ATTENTION:
Never input your actual seedphrase into this ROM on any computer
Flash this ROM to physical cartridge ONLY before use
Physical Cartridges Available Upon Completion

The intention of this ROM is to develop a secure, air-gapped environment in which to store, manage, and recover Bitcoin seed phrases and passphrases — entirely offline, on hardware that predates the internet by a decade. Built for the original Game Boy using GB Studio, this cartridge treats the simplicity of vintage hardware as a feature rather than a limitation, leveraging its inherent isolation from any network as the foundation of its security model.

Upcoming Features:

4, 6, or 8-Digit PIN protection. The vault is locked behind an 8-digit PIN required on every boot. Failed attempts are tracked and the device enforces an increasing delay between each one, making brute force attacks impractical.

Full seed phrase storage. Store a 12 or 24 word BIP-39 seed phrase entered character by character directly on the device. Words are stored as individual letter values — nothing is transmitted, saved to a computer, or exposed outside the cartridge.

Passphrase support. A BIP-39 passphrase of up to 10 characters can be stored alongside the seed phrase, supporting the full range of lowercase, uppercase, and numeric characters. The passphrase is stored separately and requires an additional confirmation step to view.

Wallet address storage. Store QR Code addresses for quick reference without PIN entry.

Decoy mode. Choose from a variety of boot-up options that ensure your cartidge appears as close to an original game as possible. Completely disguise the cartridge; inside and out. 

Emergency self-destruct. A dedicated wipe function zeros all stored data instantly and completely. Can be triggered manually from the locked screen or automatically after a defined number of failed PIN attempts. A duress PIN can also trigger a silent wipe while appearing to unlock normally.

+ MORE

THANK YOU!
-aj

This development is in progress. Any purchases will be considered a voluntary donation!
Download includes the entire GB Studio  2 Development file + ROM

! IN VERY EARLY DEVELOPMENT !