As the plug will be used as a mobile device, encryption is needed to make sure that if it physically falls to the wrong hands no information can be used against the company using the plug, and also to use the SD card as a secure token for authentication to the plug.
We are currently looking at the operation of cryptmount, a front-end to various Linux utilities used in encryption, one of them dm-crypt which has been discussed in the written part of the project.
An important feaure of cryptmount is that it enables authentication via external devices – just what we need for SD card authentication.
