Generation of a common encryption key

• US 20030133576A1
• Filed: 12/02/2002
• Published: 07/17/2003
• Est. Priority Date: 10/18/2000
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Grumiaux, Frederic
• Application Number:
  US10/149,786
• Publication Number:
  US 20030133576A1
• Time in Patent Office: Days
• US Class Current: 380/279
• CPC Class Codes: H04L 9/0833 involving conference or group key network architectures or network communication protocols for key management in group communication in a packet data network H04L63/065
• 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

A system for generating a common encryption key for secure communication between devices; the system including:

a plurality of devices, each associated with at least one unique device identifier; the plurality of devices being arranged in subgroups S_i(i=1 . . . n) of devices, with at least one of the subgroups including a plurality of devices; and

a central device including an algorithm generator for generating a key generating algorithm KGA₁ for each of the plurality of devices based on its associated unique device identifier; each of the key generating algorithms KGA_i being unique for a respective associated subgroup S_i with the key generating algorithms KGA_i being the same for each device of the same subgroup S_i; for each subgroup S_i the associated key generating algorithm KGA_i being operative to generate for devices of each subgroup S_j a common subgroup key SGK_i,j for use in communication between a device of subgroup S_i and a device of subgroup S_j; the common subgroup key SGK_i,j being generated in response to receiving any one of the device identifiers associated with devices in the subgroup S_j;

each device being associated with a respective storage for storing its associated key generating algorithm and including a processor for executing the associated key generating algorithm.

Claims

1. A system for generating a common encryption key for secure communication between devices;

the system including;

a plurality of devices, each associated with at least one unique device identifier;

the plurality of devices being arranged in subgroups S_i(i=1 . . . n) of devices, with at least one of the subgroups including a plurality of devices; and

a central device including an algorithm generator for generating a key generating algorithm KGA_i for each of the plurality of devices based on its associated unique device identifier;

each of the key generating algorithms KGA_i being unique for a respective associated subgroup S_i with the key generating algorithms KGA_i being the same for each device of the same subgroup S_i;

for each subgroup S_i the associated key generating algorithm KGA_i being operative to generate for devices of each subgroup S_j a common subgroup key SGK_i,j for use in communication between a device of subgroup S_i and a device, of subgroup S_j;

the common subgroup key SGK_i,j being generated in response to receiving any one of the device identifiers associated with a device in the subgroup S_j;

each device being associated with a respective storage for storing its associated key generating algorithm and including a processor for executing the associated key generating algorithm.

2. A system as claimed in claim 1, wherein the algorithm generator is operative to hash a unique device identifier to a subgroup identifier associated with a respective one of the subgroups and generating the key generating algorithm in dependence on the subgroup identifier.

3. A system as claimed in claim 1, wherein the key generating algorithm is operative to hash a unique device identifier to a subgroup identifier associated with a respective one of the subgroups and generating the common key in dependence on the

4. A system as claimed in claim 1, wherein at least one of the subgroups of devices is associated with predetermined functionality.

5. A system as claimed in claim 4, wherein at least devices having a respective recording, rendering or processing functionality are arranged in respective subgroups.

6. A system as claimed in claim 5, wherein a device associated with at least two respective functionalities is associated with at least two respective unique identifiers, each corresponding to a respective subgroup.

7. A system as claimed in claim 4, wherein a device is operative to, in response to receiving a device identifier from a further device in the system, is operative to hash the device identifier to a subgroup identifier associated with a respective one of the subgroups;

to determine the functionality of the further device in dependence on the subgroup identifier and to communicate with the further device in dependence on the determined functionality.

8. A system as claimed in claim 1, wherein the algorithm generator is operative to (pseudo-)randomly generate a common subgroup key SGK_i,j for each respective pair of subgroups S_i and S_j;

the key generating algorithm KGA_i associated with devices of subgroup S_i including a set SGIDR_i of representations of common subgroup keys that includes for each subgroup S_j a representation of a respective unique common subgroup key SGK_i,j.

9. A system as claimed in claim 8, wherein for each subgroup S_i the associated key generating algorithm KGA_i is operative to generate the common subgroup key SGK_i,j for use in communication to a device in the subgroup S_j by selecting a representation of the common subgroup key SGK_i,j from the set SGIDR_i of representations of common subgroup keys included in the algorithm.

10. A system as claimed in claim 8, wherein for each i and j the algorithm generator is operative to mix a device identifier of a device associated with the subgroup S_j with secret information associated with the subgroup S_i and to use the mixing output as a key for encrypting the common subgroup key SGK_i,j and using the encryption outcome as the representation of the common group key SGK_i,j.

11. A system as claimed in claim 10, wherein the key generating algorithm KGA_i associated with subgroup S_i is operative to mix a device identifier of a device associated with subgroup S_j with secret information associated with the subgroup S_i and to use the mixing output as a key for decrypting the representation of the common subgroup key SGK_i,j.

12. A system as claimed in claim 1, wherein the subgroups of devices are arranged in groups;

each group including at least one of the subgroups and at least one group including a plurality of subgroups;

each respective pair of groups G_a and G_b being associated with a unique common group key SGK_Ga^,G_b which is identical to the common subgroup key SGK_i,j for all subgroups S_i of group G_a and all subgroups S_j of group G_b.

13. A system as claimed in claim 12, wherein a device of a subgroup S_i of group G_a is operative to use the same common group key SGK_Ga^,G_b for broadcast or multicast communication to a plurality of devices of at least one subgroup S_j of group G_b.

14. A central device for use in a system for generating a key generating algorithm for secure communication between devices, each of a plurality of devices being associated with at least one unique device identifier;

the plurality of devices being arranged in subgroups S_i(i=1 . . . n) of devices, with at least one of the subgroups including a plurality of devices;

the central device including an algorithm generator for generating a key generating algorithm KGA_i for each of the plurality of devices based on its associated unique device identifier;

each of the key generating algorithms KGA_i being unique for a respective associated subgroup S_i with the key generating algorithms KGA_i being the same for each device of the same subgroup S_i;

for each subgroup S_i the associated key generating algorithm KGA_i being operative to generate for devices of each subgroup S_j a common subgroup key SGK_i,j for use in communication between a device of subgroup S_i and a device of subgroup S_j;

the common subgroup key SGK_i,j being generated in response to receiving any one of the device identifiers associated with a device in the subgroup S_j.

15. A device for securely communicating to another device using a common encryption key;

the device being associated with at least one unique device identifier and being a member of one of a plurality of subgroups S_i(i=1 . . . n) of devices, with at least one of the subgroups including a plurality of devices;

the device being associated with a respective storage for storing an associated key generating algorithm and including a processor for executing the associated key generating algorithm;

the key generating algorithms KGAi being unique for the associated subgroup S_i with the key generating algorithms KGAi being the same for each device of the same subgroup S_i;

the key generating algorithm KGAi being operative to generate for devices of each subgroup S_j a common subgroup key SG_i,j for use in communication with a device of subgroup S_j;

the common subgroup key SGK_i,j being generated in response to receiving any one of the device identifiers associated with a device in the subgroup S_j.

16. A method for generating a key generating algorithm for secure communication between devices in a system, where the system includes a plurality of devices, each associated with at least one unique device identifier;

the plurality of devices being arranged in subgroups S_i(i=1 . . . n) of devices, with at least one of the subgroups including a plurality of devices;

the method including generating a key generating algorithm KGAi for each of the plurality of devices based on its associated unique device identifier;

each of the key generating algorithms KGAi being unique for a respective associated subgroup S_i with the key generating algorithms KGAi being the same for each device of the same subgroup S_i;

for each subgroup S_i the associated key generating algorithm KGA_i,j being operative to generate for devices of each subgroup S_j a common subgroup key SGK_i,j for use in communication between a device of subgroup S_i and a device of subgroup S_j;

the common subgroup key SGK_i,j being generated in response to receiving any one of the device identifiers associated with a device in the subgroup S_j.

17. A computer program product, wherein the program product is operative to perform the method of claim 16.

18. A method for generating a common encryption key for secure communication between devices;

each of the devices being associated with at least one unique device identifier;

- and each of the devices being a member of one of a plurality of subgroups S_i(i=1 . . . n) of devices, with at least one of the subgroups including a plurality of devices;

the method including using a key generating algorithm KGAi, which is unique for a subgroup S_i with the key generating algorithms KGAi being the same for each device of the same subgroup S_i, to generate for devices of each subgroup S_j a common subgroup key SGK_i,j for use in communication between a device of subgroup S_i and a device of subgroup S_j;

the common subgroup key SGK_i,j being generated in response to receiving any one of the device identifiers associated with a device in the subgroup S_i.

19. A computer program product, wherein the program product is operative to perform the method of claim 18.