Patent ID: 7343493

Claim:
A method for enabling access to an encryption key of an encryption file system (EFS) within a computer platform, said method comprising: storing said encryption key on a storage medium that requires correct authorization data before said encryption key can be expected, wherein said encryption is stored in a format that is only decipherable within said storage medium by processing components of said storage medium; sealing said encryption key to a state of one or more platform control registers (PCRs), wherein said one or more PCRs may be modified by a secure hashing algorithm (SHA) during a boot operation of the computer system; and responsive to a determination following the boot operation that the value of said one or more PCRs matches predetermined values provided as the correct authorization data for said encryption key on said storage medium, first decrypting said encryption key, utilizing code which is stored within said storage medium, that is expected to initiate decryption the encryption key when the encryption key is stored in encryption format but required in unencrypted format to access the EFS; and exporting said encryption key from said storage medium and enabling access to said EFS utilizing said encryption key; dynamically changing a value of at least one of said one or more PCRs immediately following said determination, wherein said encryption key is exported only at the time said determination is completed and said PCR values match said predetermined values, wherein further said dynamically changing step occurs immediately after said exporting step and prior to access by users to said computer platform; and storing said key is memory following said decrypting and exporting, wherein said key is utilized to decrypt a second key that is utilized by other files of said file system and subsequently open said other files as requested by a user.