US 7,607,025 B1 · Methods of intrusion detection and prevention in secure programmable logic devices

Abstract

Methods of securing a programmable logic device (PLD) when an intrusion attempt is detected, e.g., methods of erasing sensitive data from the PLD or disabling configuration of the PLD in response to an attack. For example, when an attempt is made to configure the PLD with an unauthorized bitstream, a decryption key stored on the PLD can be erased, or decryption logic in the PLD can be otherwise disabled. The criteria for assuming that an attack is in progress can include, for example, the lack of a cyclic redundancy check (CRC) value included with a configuration bitstream, an attempt to operate the PLD outside normal operating ranges, receipt of an incorrect CRC value, or receipt of a predetermined number of bitstreams including incorrect CRC values. In some embodiments, an error correction procedure is performed on the bitstream, thereby preventing most transmission errors from being incorrectly interpreted as an attack.

Claims26

Dependent claims

A method of securing a programmable logic device (PLD), comprising:

receiving a bitstream for the PLD;
detecting an unauthorized attempt to obtain information about a design targeted to the PLD;
wherein the attempt is detected as unauthorized in response to an invalid cyclic redundancy check (CRC) value for the bitstream;
and
erasing sensitive data from the PLD in response to the attempt,
wherein the sensitive data erased from the PLD comprises a decryption key,
wherein the sensitive data erased from the PLD further comprises configuration data, and
wherein the erasing includes operating circuitry of the PLD to clear the sensitive data from memory cells of the PLD.

5 more elements

A method of detecting and preventing unauthorized reconfiguration of a programmable logic device (PLD), comprising:

detecting an attempt to configure the PLD with an unauthorized encrypted bitstream;
wherein the attempt is detected as unauthorized in response to an invalid cyclic redundancy check (CRC) value for the bitstream;
and
disabling, in response to the attempt, a bitstream decryption function in the PLD,
wherein the disabling of the bitstream decryption function in the PLD comprises preventing, in response to the attempt, further configuration of the PLD until a new decryption key is stored in the PLD,
wherein preventing further configuration of the PLD until a new decryption key is stored in the PLD comprises erasing an existing decryption key stored in the PLD, and
wherein the erasing includes operating circuitry of the PLD to clear the sensitive data from memory cells of the PLD.

4 more elements

Dependencies are inferred from the claim text.

Methods of intrusion detection and prevention in secure programmable logic devices

Life of this patent

Methods of intrusion detection and prevention in secure programmable logic devices

Life of this patent

Abstract

Claims26