HARDWARE-BASED KEY GENERATION AND RECOVERY

• US 20120198244A1
• Filed: 04/12/2012
• Published: 08/02/2012
• Est. Priority Date: 10/13/2009
• Status: Active Grant

• Current Assignee: Lockheed Martin Missiles & Fire Control (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Missiles & Fire Control (Martin Marietta Corporation)
• Inventors: NELSON, Patrick A., Adams, Christian
• Granted Patent: US 8,499,172 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06F 21/73 by creating or determining hardware identification, e.g. serial numbers
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H04L 9/0872 using geo-location information, e.g. location data, time, relative position or proximity to other entities
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

A system and method of recovering encoded information contained in a device by storing and retrieving at least part of the necessary decoding data by setting and measuring the physical characteristics of the device. Storage and recovery options include, but are not limited to, measurement of electronic or optical characteristics of electrically or optically conductive portions of the device using a range of measurement techniques that include, but are not limited to, time-domain reflectometry.

Claims

1-46. -46. (canceled)

47. A method of recovering information embedded in a medium, the method comprising:

measuring a physical characteristic of the medium between a beginning point and an end point;

generating a value in response to measuring the characteristic; and

generating a representation of the embedded information based on the generated value by encoding said generated value.

48. The method of claim 47, the method further comprising generating an encrypted key based on the encoded value.

49. The method of claim 47, where the medium includes signal conductor with predetermined transmission characteristics, and where

said measuring includes

passing a signal through the conductor from a measurement starting point to a measurement ending point;

and

measuring a property of the signal conductor by comparing the signal at the measurement starting point and with the signal at the measurement ending point.

50. The method of claim 47, said generated representation of the embedded information including an access key for an encrypted device whose operation is contingent on receipt of a valid access key.

51. The method of claim 50, the method further comprising providing the access to the encrypted device, where providing an invalid access key causes the encrypted device to become permanently inoperable.

52. The method of claim 48, where the encrypted key is a decryption key to decrypt data stored in an encrypted memory operably connected to the medium.

53. The method of claim 48, the method further comprising:

determining if the generated key is a correct key by comparing the generated value to a predetermined value based on an expected measurement for said physical characteristic.

54. The method of claim 47, where the generated value is predetermined based on the embedded information such that damage or alteration to the medium or a change in a measurement technique prevents the recovery of the embedded information.

55. The method of claim 47, where generating a representation includes:

creating a binary number with a number of bits determined by a length of time elapsed during said measuring, where a value of the binary number is determined by a value of the measured physical characteristic during said length of time.

56. The method of claim 55, where the length of time is measured in discrete intervals such that each bit is associated with a discrete interval, and where a bit value is determined by a value of the measured physical characteristic during said discrete interval.

57. An apparatus for recovering information embedded in a medium, the apparatus comprising:

a measurement unit that measures a physical characteristic of the medium between a beginning point and an end point;

a value generator that generates a value based on the measured characteristic; and

an information recovery portion that generates a representation of the embedded information based on the generated value by encoding said generated value.

58. The apparatus of claim 57, where the information recovery portion generates an encrypted key based on the encoded value.

59. The apparatus of claim 57, where:

the medium includes signal conductor with predetermined transmission characteristics, and

the measurement unit measures a physical characteristic of said conductor by

passing a signal through the conductor from a measurement starting point to a measurement ending point; and

measuring a property of the signal conductor by comparing the signal at the measurement starting point and with the signal at the measurement ending point.

60. The apparatus of claim 57, the apparatus further comprising an encrypted device whose operation is contingent on receipts of a valid access key;

where the generated representation of the embedded information includes information representing an access key for the encrypted device; and

where said encrypted device is operably connected to said information recovery portion.

61. The apparatus of claim 60, where the encrypted device is configured such that providing an invalid access key to the encrypted device causes the encrypted device to become permanently inoperable.

62. The apparatus of claim 58, the apparatus further comprising an encrypted memory operably connected to the information recovery portion;

where the encrypted key is a decryption key to decrypt data stored in said memory.

63. The apparatus of claim 58, where the information recovery portion determines if the generated key is a correct key by comparing the generated value to a predetermined value based on an expected measurement for said physical characteristic.

64. The apparatus of claim 57, where the generated value is predetermined based on the embedded information such that damage or alteration to the medium or a change in a measurement technique prevents the recovery of the embedded information.

65. The apparatus of claim 57, the apparatus further comprising a clock;

and

where said clock measures a length of time elapsed during said measuring; and

where the information recovery portion generates said representation by creating a binary number with a number of bits determined by said length of time, where a value of the binary number is determined by a value of the measured physical characteristic during said length of time.

66. The apparatus of claim 65, where the clock measures said length of time in discrete intervals such that each bit is associated with a discrete interval, and where a bit value is determined by a value of the measured physical characteristic during said discrete interval.