Trust information delivery scheme for certificate validation

• US 9,288,064 B2
• Filed: 12/15/2014
• Issued: 03/15/2016
• Est. Priority Date: 06/11/1999
• Status: Expired due to Term

• Current Assignee: Comcast Cable Communications Management LLC (Comcast Corporation)
• Original Assignee: TVWorks LLC (Comcast Corporation)
• Inventors: Xiao, Sihai
• Primary Examiner(s): Zee, Edward
• Application Number:
  US14/570,417
• Publication Number:
  US 20150100786A1
• Time in Patent Office: 456 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 21/33 using certificates
• CPC Class Codes: G06F 21/604 Tools and structures for managing or administering access control systems
• CPC Class Codes: G06F 2221/2145 Inheriting rights or properties, e.g., propagation of permissions or restrictions within a hierarchy
• CPC Class Codes: G06F 2221/2151 Time stamp
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3239 involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD
• CPC Class Codes: H04L 9/3265 using certificate chains, trees or paths; Hierarchical trust model
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]

Abstract

A unique TIO based trust information delivery scheme is disclosed that allows clients to verify received certificates and to control Java and Javascript access efficiently. This scheme fits into the certificate verification process in SSL to provide a secure connection between a client and a Web server. In particular, the scheme is well suited for incorporation into consumer devices that have a limited footprint, such as set-top boxes, cell phones, and handheld computers. Furthermore, the TIO update scheme disclosed herein allows clients to update certificates securely and dynamically.

Claims

1. A method comprising:

receiving, from a computing device, an unverified root certificate, wherein the unverified root certificate is for certifying the computing device;

hashing a public key portion of the unverified root certificate to generate a digest;

certifying the computing device responsive to the digest matching one of a first plurality of previously stored hash values;

receiving a trust information object comprising a second plurality of hash values and a plurality of trust vectors; and

overwriting the first plurality of previously stored hash values and a plurality of previously stored trust vectors with the second plurality of hash values and the plurality of trust vectors, respectively.

2. The method of claim 1, wherein the unverified root certificate comprises a signing certificate associated with one of a certificate authority, a software provider, and a content provider.

3. The method of claim 1, wherein the hashing is performed via an MD5 or SHA-1 algorithm.

4. The method of claim 1, wherein the first plurality of previously stored hash values is associated with an earlier timestamp than the second plurality of hash values.

5. The method of claim 1, further comprising:

determining that the computing device is trusted for a secure connection by examining a bit of one of the plurality of previously stored trust vectors; and

establishing the secure connection.

6. The method of claim 1, further comprising:

receiving information related to a number of signatures required for a next update of the second plurality of hash values.

7. A method comprising:

receiving, from a computing device, a certificate chain comprising a plurality of unverified certificates, wherein the plurality of unverified certificates comprises a first unverified certificate of a certificate authority issuing the plurality of unverified certificates;

hashing the first unverified certificate to generate a digest;

certifying the computing device responsive to the digest matching one of a first plurality of previously stored hash values;

starting a session with the computing device;

receiving a second plurality of hash values and a plurality of trust vectors; and

overwriting the first plurality of previously stored hash values and a plurality of previously stored trust vectors with the second plurality of hash values and the plurality of trust vectors, respectively.

8. The method of claim 7, wherein the receiving the second plurality of hash values and the plurality of trust vectors comprises receiving the second plurality of hash values and the plurality of trust vectors via a secure transmission channel.

9. The method of claim 7, wherein the certificate chain comprises a signing certificate associated with one of the certificate authority, a software provider, and a content provider.

10. The method of claim 7, wherein the hashing is performed via an MD5 or SHA-1 algorithm.

11. The method of claim 7, wherein the first plurality of previously stored hash values is associated with an earlier timestamp than the second plurality of hash values.

12. The method of claim 7, further comprising:

determining that the computing device is trusted for a secure connection by examining a bit of one of the plurality of previously stored trust vectors; and

establishing the secure connection.

13. The method of claim 7, further comprising:

receiving information related to a number of signatures required for a next update of the second plurality of hash values.

14. A method comprising:

receiving, from a computing device, a first trust information object comprising at least a plurality of hash values, each hash value being hashed from a trusted entity certificate, and a plurality of trust vectors, each trust vector corresponding to one of the plurality of hash values, the trust vectors indicative of a level of trust associated with a particular trusted entity certificate;

receiving, from the computing device, an unverified root certificate, wherein the unverified root certificate is for certifying the computing device;

hashing a public key portion of the unverified root certificate to generate a digest;

determining that the digest matches one of a first plurality of previously stored hash values;

starting a session with the computing device;

receiving a second trust information object; and

overwriting the first trust information object with the second trust information object.

15. The method of claim 14, wherein the unverified root certificate comprises a signing certificate associated with one of a certificate authority, a software provider, and a content provider.

16. The method of claim 14, wherein the hashing is performed via an MD5 or SHA-1 algorithm.

17. The method of claim 14, wherein the first trust information object is associated with an earlier timestamp than the second trust information object.

18. The method of claim 15, further comprising:

determining that the computing device is trusted for a secure connection by examining a bit of a previously stored trust vector associated with the digest; and

establishing the secure connection.

19. The method of claim 14, further comprising:

receiving information related to a number of signatures required for a next update of the second trust information object.