Think whole-disk encryption. I have a similar situation where I need to encrypt some data on a device (embedded, not PC) but that data needs to be decrypted and used when the device is booted up. The problem is, there is no user interface available and it wouldn’t make sense to store the key for the data on the drive as well in plaintext.
Whole-disk encryption on the PC has the advantage of either storing the key in the cloud or accepting it via an external device such as a USB key. However, my constraints include no network access at times as well as no support for external USB devices. What would be he most security sounded option to store a key for encrypted data on disk with such constraints?