Patent ID: 9342699
Filing Date: 2016-05-17
CPC Classification: G06F,G11B

Claim Text:
1. A method comprising: controlling access to encrypted data files, stored at a memory of a device, the encrypted data files categorized according to a plurality of categories, each encrypted data file encrypted using one or more respective file encryption keys, each respective file encryption key in a category encrypted using a respective category key respective to the category, the respective category key encrypted using a respective domain master key respective to the category, the respective domain master key available using a system master key, which is turn encrypted using a processor key stored at a processor of the device, the system master key configured to protect each of respective domain master keys of each of the plurality of categories; and, controlling access to the encrypted data files by: upon startup of the device, decrypting the system master key using the processor key; and, when criteria associated with the category is met: one or more of decrypting or generating the respective domain master key; decrypting the respective category key using the respective domain master key; decrypting the one or more respective file encryption keys using the respective domain master key; destroying an unencrypted respective domain master key after the one or more respective file encryption keys are decrypted, the criteria comprising one or more of: the device being turned on; receiving a password at an input device of the device that matches password data stored at the memory; or receiving a personal identification number at the input device that matches data read from an external memory reader of the device.