Roaming hardware paired encryption key generation

• US 20040057579A1
• Filed: 09/20/2002
• Published: 03/25/2004
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: Cable Television Laboratories Incorporated
• Original Assignee: Cable Television Laboratories Incorporated
• Inventors: Fahrny, James W.
• Granted Patent: US 7,634,659 B2
• Time in Patent Office: Days
• US Class Current: 380/44
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics

Abstract

The roaming hardware paired encryption key generation coalesces a content variable with a network, or subnet, address to generate an encryption key. The source generates a content identification that is unique to the content being encrypted and the network, or subnet, address is coalesced with the content identification to generate a unique encryption key for the content being encrypted. The encrypted digital content is transmitted to the destination devices identified by the network, or subnet address, along with the content identification. At the destination, the destination devices regenerate the encryption by coalescing the content identification and the network, or subnet, address in the same manner as coalesced at the source device. After regenerating the encryption key, the ciphertext is decrypted into plaintext.

Claims

1. A method for generating an encryption key for use by a host device to encrypt data for access by multiple devices connected on a network, said method comprising:

generating a content identification;

retrieving a network address that is unique to said multiple devices;

using both said content identification and said network address to produce said encryption key.

2. The method of claim 1 wherein said using comprises:

hashing said content identification to produce a first hashed variable;

hashing said network address to produce a second hashed variable; and

coalescing said first hashed variable and said second hashed variable to produce said encryption key.

3. The method of claim 3 wherein generating a content identification comprises:

generating a random variable by said host device.

4. The method of claim 3 further comprising:

encrypting said data with said encryption key to produce a ciphertext;

attaching said random variable and said network address to said ciphertext for transmission to said multiple devices identified by said network address over said network.

5. The encryption method of claim 4 for further use decrypting said ciphertext, the method comprising:

retrieving said random variable attached to said ciphertext;

retrieving said network address attached to said ciphertext;

coalescing said random variable and said network address to produce said encryption key; and

decrypting said ciphertext with said encryption key to produce said data.

6. The encryption method of claim 3 further comprising:

encrypting said data with said encryption key to produce a ciphertext;

attaching said network address to said ciphertext;

transmitting said ciphertext and said attached network address to said multiple devices identified by said network address over said network; and

transmitting said random variable to said multiple devices identified by said network address over said network.

7. The encryption method of claim 6 for further use decrypting said ciphertext, the method comprising:

retrieving said random variable;

retrieving said network address;

coalescing said random variable and said network address to produce said encryption key; and

decrypting said ciphertext with said encryption key to produce said data.

8. A method for encrypting data for distribution to a selected plurality of devices that are connected to a network that has a network address, wherein said network address includes an address common to said selected plurality of devices, the method comprising:

retrieving said network address;

generating a random variable for said data;

generating an encryption key from said network address and said random variable;

encrypting said data using said encryption key to produce a ciphertext; and

transmitting said ciphertext to said selected plurality of devices, identified by said network address, over said network.

9. The method of claim 8 wherein said selected plurality of devices are connected to said network as a subnet that is distinguished from said network by a subnet address.

10. The method of claim 9 further comprising:

attaching said random variable to said ciphertext for transmission to said selected plurality of devices.

11. The encryption method of claim 10 for further use decrypting said ciphertext, the method comprising:

retrieving said random variable attached to said ciphertext;

retrieving said subnet address from said network address;

coalescing said random variable and said subnet address to produce said encryption key; and

decrypting said ciphertext with said encryption key to produce said data.

12. The encryption method of claim 9 further comprising:

transmitting said ransom variable to said selected plurality of devices identified by said subnet address over said network.

13. The encryption method of claim 12 for further use decrypting said block of ciphertext, the method comprising:

retrieving said random variable;

retrieving said subnet address from said network address;

coalescing said random variable and said subnet address to produce said encryption key; and

decrypting said ciphertext with said encryption key to produce said data.