Multiple level access system

• US 6,754,820 B1
• Filed: 01/30/2002
• Issued: 06/22/2004
• Est. Priority Date: 01/30/2001
• Status: Expired due to Term

• Current Assignee: TecSec, Incorporated
• Original Assignee: TecSec, Incorporated
• Inventors: Scheidt, Edward M., Domangue, Ersin
• Primary Examiner(s): Jean, Frantz B.
• Assistant Examiner(s): Arani, Taghi T.
• Application Number:
  US10/060,011
• Time in Patent Office: 874 Days
• Field of Search: 713/201-202, 713/166, 713/184-187, 380/286, 380/277, 380/30
• US Class Current: 713/166
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 21/6245 Protecting personal data, e.g. for financial or medical purposes
• CPC Class Codes: G06F 2221/2113 Multi-level security, e.g. mandatory access control
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/3829 involving key management
• CPC Class Codes: H04L 2463/062 applying encryption of the keys cryptographic mechanisms or cryptographic arrangements for key distribution using key encryption key H04L9/0822
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/068 using time-dependent keys, e.g. periodically changing keys cryptographic mechanisms or cryptographic arrangements for controlling usage of secret information H04L9/088
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• CPC Class Codes: H04L 63/105 Multiple levels of security
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials

Abstract

A method of securing an object at an access level includes selecting a profile for a user, including a credential having an encrypted credential public key, an encrypted credential public key encryption key, and a multiple-level access identifier. A working key is generated by binding a domain value with a random value. The object is encrypted with the working key. A random value encryption key is generated based on the shared value by decrypting the credential public key encryption key with the profile key encryption key, decrypting the credential public key with the credential public key encryption key, generating an ephemeral key pair, and generating a shared value based on the ephemeral private key and the credential public key. The random value is encrypted with the random value encryption key, and the encrypted object, the ephemeral public key, and the encrypted random value are provided for an authorized recipient.

Claims

1. In a multi-level access system, a method of securing an object at a multiple-level access level, comprising:

receiving from a user, a profile key encryption key corresponding to the multiple-level access level;

selecting an object to secure;

selecting a profile associated with the user, wherein the profile includes

a domain value,

an encrypted profile encryption key, and

a credential, wherein the credential includes

an encrypted credential public key,

an encrypted credential public key encryption key, and

a multiple-level access identifier;

selecting the credential based on a comparison of the multiple-level access level and the multiple-level access identifier;

generating a working key, including

generating a random value, and

binding at least the domain value and the random value together to form the working key;

encrypting the object with the working key;

generating a random value encryption key, including

decrypting the encrypted credential public key encryption key with at least the profile key encryption key,

decrypting the encrypted credential public key with at least the decrypted credential public key encryption key,

generating an ephemeral key pair including an ephemeral private key and an ephemeral public key,

generating a shared value based on at least the ephemeral private key and the decrypted credential public key, and

generating the random value encryption key based on at least the shared value;

encrypting the random value with at least the random value encryption key; and

providing the encrypted object, the ephemeral public key, and the encrypted random value for an authorized recipient;

wherein

the profile further includes a profile initialization vector,

decrypting the encrypted credential public key encryption key includes decrypting the encrypted credential public key encryption key with the profile key encryption key and the profile initialization vector,

the credential further includes a credential initialization vector,

decrypting the encrypted credential public key includes decrypting the encrypted credential public key with the decrypted credential public key encryption key and the credential initialization vector, and

the multiple-level access level is lower than the multiple-level access identifier.

2. The method of claim 1, wherein the multiple-level access level corresponds to the multiple-level access identifier.

3. The method of claim 1, wherein the multiple-level access level is identical to the multiple-level access identifier.

4. In a multi-level access system, a method of securing an object at a multiple-level access level, comprising:

receiving, from a user, a profile key encryption key corresponding to the multiple-level access level;

selecting an object to secure;

selecting a profile associated with the user, wherein the profile includes

a domain value,

an encrypted profile encryption key, and

a credential, wherein the credential includes

an encrypted credential public key,

an encrypted credential public key encryption key, and

a multiple-level access identifier;

selecting the credential based on a comparison of the multiple-level access level and the multiple-level access identifier;

generating a working key, including

generating a random value, and

binding at least the domain value and the random value together to form the working key;

encrypting the object with the working key;

generating a random value encryption key, including

decrypting the encrypted credential public key encryption key with at least the profile key encryption key,

decrypting the encrypted credential public key with at least the decrypted credential public key encryption key,

generating an ephemeral key pair including an ephemeral private key and an ephemeral public key,

generating a shared value based on at least the ephemeral private key and the decrypted credential public key, and

generating the random value encryption key based on at least the shared value;

encrypting the random value with at least the random value encryption key; and

providing the encrypted object, the ephemeral public key, and the encrypted random value for an authorized recipient;

wherein

the profile further includes a profile initialization vector,

decrypting the encrypted credential public key encryption key includes decrypting the encrypted credential public key encryption key with the profile key encryption key and the profile initialization vector,

the credential further includes a credential initialization vector,

decrypting the encrypted credential public key includes decrypting the encrypted credential public key with the decrypted credential public key encryption key and the credential initialization vector, and

the multiple-level access level is higher than the multiple-level access identifier.

5. The method of claim 4, wherein the multiple-level access level corresponds to the multiple-level access identifier.

6. The method of claim 4, wherein the multiple-level access level is identical to the multiple-level access identifier.