Replacing blinded authentication authority

• US 9,009,483 B2
• Filed: 08/24/2011
• Issued: 04/14/2015
• Est. Priority Date: 12/22/2003
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wood, Matthew D., Brickell, Ernie
• Primary Examiner(s): Davis, Zachary A
• Application Number:
  US13/217,151
• Publication Number:
  US 20110307704A1
• Time in Patent Office: 1,329 Days
• Field of Search: 713/180, 713/176, 713/178, 726/5, 726/6, 726/9, 380/277
• US Class Current: 713/180
• CPC Class Codes: G06F 21/33 using certificates
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 2221/2151 Time stamp
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/3257 using blind signatures
• CPC Class Codes: H04L 9/3297 involving time stamps, e.g. generation of time stamps

Abstract

A manufacturing entity provides a blinded signature to a secure device and associates a time with the blinded signature. If a signing key is compromised, the manufacturing entity provides a time of the compromise and the time associated with the blinded signature to the replacement authority.

Claims

1. A method comprising:

detecting, at a manufacturing entity, that a signing key has been compromised, wherein the manufacturing entity has used the signing key to authenticate one or more secure devices; and

providing, from the manufacturing entity to a replacement authority, a blinded identity ticket associated with a first secure device having a certificate to be replaced due to the compromise, wherein the blinded identity ticket is separate from the certificate that is to be replaced for the first secure device, wherein the manufacturing entity is separate from the replacement authority and the replacement authority is to authenticate the first secure device and provide a new certificate to the first secure device.

2. The method of claim 1 further comprising at a time prior to detecting the compromise:

receiving a blinded identity and the blinded identity ticket from the first secure device;

signing the blinded identity using the signing key to create a blinded identity signature for the first secure device; and

sending the blinded identity signature to the first secure device to enable the first secure device to obtain the certificate.

3. The method of claim 2 further comprising:

obtaining and storing a time stamp on the received blinded identity ticket from the first secure device, wherein the time stamp is a time of signing the blinded identity signature.

4. The method of claim 3 further comprising:

in response to the detection that the signing key has been compromised, providing a time of the compromise of the signing key to the replacement authority; and

wherein the first secure device is to provide the time stamp on the received blinded identity ticket to the replacement authority.

5. The method of claim 1 wherein the first secure device generates the blinded identity ticket using a secret identity of the first secure device, the secret identity generated by the first secure device.

6. A method comprising:

receiving, at a replacement authority from a manufacturing entity, a time of compromise of a signing key and a blinded identity ticket associated with a first secure device that is to be authenticated with another signing key having a certificate to be replaced due to the compromise, the blinded identity ticket separate from the certificate for the first secure device;

comparing a time stamp on the blinded identity ticket associated with the first secure device with the time of compromise of the signing key; and

authenticating the first secure device and providing a new blinded identity signature to the first secure device in response to determining that a time of signing the blinded identity ticket for the first secure device with the signing key indicated by the time stamp on the blinded identity ticket is earlier than the time of compromise of the signing key, wherein the replacement authority is separate from the manufacturing entity.

7. The method of claim 6 further comprising:

receiving a blinded identity and a second blinded identity ticket from the first secure device; and

signing the blinded identity using a second signing key to create the new blinded identity signature for the first secure device.

8. A non-transitory machine-readable medium having stored thereon instructions, which if performed by a machine of a manufacturing entity cause the machine to perform a method comprising:

detecting, at the manufacturing entity, that a signing key has been compromised, wherein the signing key has been used to authenticate a first secure device; and

providing, from the manufacturing entity to a replacement authority, a blinded identity ticket associated with the first secure device having a certificate to be replaced due to the compromise, the blinded identity ticket separate from the certificate that is to be replaced for the first secure device, wherein the manufacturing entity is separate from the replacement authority and the replacement authority is to authenticate the first secure device and provide a new certificate to the first secure device.

9. The non-transitory machine-readable medium of claim 8 wherein the method further comprises at a time prior to detecting the compromise:

receiving a blinded identity and the blinded identity ticket from the first secure device;

signing the blinded identity using the signing key to create a blinded identity signature for the first secure device; and

sending the blinded identity signature to the first secure device to enable the first secure device to obtain the certificate.

10. The non-transitory machine-readable medium of claim 9 wherein the method further comprises:

obtaining and storing a time stamp on the received blinded identity ticket from the first secure device, wherein the time stamp is a time of signing the blinded identity signature.

11. The non-transitory machine-readable medium of claim 10 wherein the method further comprises:

in response to the detection that the signing key has been compromised, providing a time of the compromise of the signing key to the replacement authority; and

wherein the first secure device is to provide the time stamp on the received blinded identity ticket to the replacement authority.