Method of accessing functions of an embedded device
AssigneeSchneider Electric Automation GmbH
InventorsRalf Berner, Thomas Gleixner
Life of this patent
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Abstract
A method for accessing functions of an embedded device, for example a controller programmable from memory, wherein function blocks of the embedded device are assigned to at least two hierarchically superimposed levels, an access to a function block of the embedded device occurs from outside of the embedded device by a data interface, and for access an authentication must occur for the level to which the respective function block is assigned, and again for each individual level above the level to which the function block is assigned, to permit execution of a function of the function block, wherein the functions of the function blocks permit access to a firmware of the embedded device.
Claims20
A method of accessing functions of an embedded device, the method comprising:
- (a) associating functional blocks of the embedded device with at least two levels disposed above one another hierarchically;
- (b) accessing to a functional block of the embedded device from outside the embedded device by a data interface;
- and
- (c) authenticating during the accessing for a level with which the respective functional block is associated, and subsequently and serially performing an authentication for every level above the level associated with the functional block to permit an execution of a function of the functional block, each authentication performed being a prerequisite for a subsequent authentication,
- wherein the functions of the functional blocks permit access to firmware of the embedded device,
- for each level of the at least two levels, successful authentication permits access to associated functional blocks, and
- authentication for each of the at least two levels includes transmission of a one-time-use value to a device requesting access, receipt of an encrypted value from the device requesting access, decryption of the encrypted value to generate a decrypted value, determining whether the decrypted value matches the one-time-use value, and determination that authentication is successful when the decrypted value matches the one-time-use value.
An embedded device comprising:
- a data interface;
- a processing device;
- and
- a memory device;
- wherein the processing device is configured to:
- a) associate functional blocks of the embedded device with levels disposed above one another hierarchically;
- b) carry out an authentication during access to a functional block of the embedded device from outside the embedded device by the data interface for a level with which the functional block is associated, and subsequently and serially carry out an authentication for every level disposed above the level associated with the functional block before an execution of a function of the functional block is permitted, each authentication performed being a prerequisite for a subsequent authentication,
- wherein functions of the functional blocks permit access to firmware of the embedded device,
- for each level of the at least two levels, successful authentication permits access to associated functional blocks, and
- authentication for each of the at least two levels includes transmission of a one-time-use value to a device requesting access, receipt of an encrypted value from the device requesting access, decryption of the encrypted value to generate a decrypted value, determining whether the decrypted value matches the one-time-use value, and determination that authentication is successful when the decrypted value matches the one-time-use value.
Dependencies are inferred from the claim text.