A system for securely customizing a computing environment based on cryptographic protections includes providing a key device; bringing the key device proximate to a computing environment (510); beginning an authentication protocol when the user approaches the environment with the device; validating user to the key device (520); comparing certificates (525); unlocking/regenerating a device split key (530); if authentication of certificates is not valid, log & return (540); if it is valid, a full key is generated on the computing environment in volatile memory, and the full key unlocks personal settings on the computing environment (545). Using the computing environment with the personal settings (550); disconnecting (555); and logging activity (560). The device can be a smart phone. Bringing the key proximate to a computing environment (510) can initiate Bluetooth or other near field communications. Initial steps can include enrolling the key (505). The environment can be a vehicle.