Method of ciphering data transmission in a radio system

• US 7,602,917 B2
• Filed: 12/15/2004
• Issued: 10/13/2009
• Est. Priority Date: 03/08/1999
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Longoni, Fabio, Vialen, Jukka
• Primary Examiner(s): Tran; Ellen
• Application Number:
  US11/013,184
• Publication Number:
  US 20060120530A1
• Time in Patent Office: 1,763 Days
• Field of Search: 380/270, 380/43, 380/44, 380/47, 380/272, 380/34
• US Class Current: 380/270
• CPC Class Codes: H04L 2209/046 of operations, operands or results of the operations
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 9/065 Encryption by serially and continuously modifying data stream elements, e.g. stream cipher systems, RC4, SEAL or A5/3
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic

Abstract

The invention relates to a method of ciphering data transmission in a radio system, and to a user equipment using the method, and to a radio network subsystem using the method. The method includes the steps of: (602) generating a ciphering key; (604A) producing a ciphering mask in a ciphering algorithm using the ciphering key as an input parameter; (604B) using a logical channel specific parameter or a transport channel specific parameter as an additional input parameter to the ciphering algorithm; and (606) producing ciphered data by applying the ciphering mask to plain data.

Claims

1. A method comprising:

generating a ciphering key;

producing a ciphering mask in a ciphering algorithm using the ciphering key as an input parameter,

producing ciphered data by applying the ciphering mask to plain data; and

using a logical channel identifying parameter or a transport channel identifying parameter as an additional input parameter to the ciphering algorithm;

wherein the plain data includes Radio Link Control Layer Protocol Data Units from at least two parallel logical channels for communication with one user equipment, and for each logical channel an individual ciphering mask is produced.

2. The method as claimed in claim 1, further comprising using the direction of transmission as an additional input parameter to the ciphering algorithm.

3. The method as claimed in claim 1, wherein the logical channel identifying parameter is one of the following:

a Radio Access Bearer Identifier, a Logical Channel Identifier, or a Signaling Link Identifier.

4. The method as claimed in claim 1, wherein the transport channel identifying parameter is a Dedicated Channel Identifier.

5. The method as claimed in claim 1, further comprising using a radio frame identifying parameter as an additional input parameter to the ciphering algorithm.

6. The method as claimed in claim 5, wherein the radio frame identifying parameter is a User Equipment Frame Number.

7. The method as claimed in claim 1, wherein a Radio Link Control Layer Protocol Data Unit of at least one logical channel is already ciphered, and wherein producing ciphered data is not repeated for said already ciphered Radio Link Control Layer Protocol Data Unit.

8. The method as claimed in claim 1, wherein the plain data further includes at least two successive Radio Link Control Layer Protocol Data Units of one logical channel, and further comprising using for each Radio Link Control Layer Protocol Data Unit of one logical channel a different part of the ciphering mask in producing the ciphered data.

9. The method as claimed in claim 1, further comprising performing the ciphering in the Medium Access Control Layer of a protocol stack.

10. The method as claimed in claim 1, further comprising producing a new ciphering mask for each radio frame of the physical layer of the protocol stack.

11. The method as claimed in claim 1, further comprising producing a new ciphering mask for each interleaving period of the physical layer of the protocol stack.

12. An apparatus comprising:

a generator configured to generate a ciphering key;

a ciphering algorithm device connected with the generator, said device configured to produce a ciphering mask using the ciphering key as an input parameter,

a ciphering circuit connected with the ciphering algorithm device, said circuit configured to produce ciphered data by applying the ciphering mask to plain data; and

the ciphering algorithm device being configured to use a logical channel identifying parameter or a transport channel identifying parameter as an additional input parameter,

wherein the ciphering circuit is configured to accept plain data including Radio Link Control Layer Protocol Data Units from at least two parallel logical channels, and the ciphering algorithm device is configured to produce for each logical channel an individual ciphering mask and the ciphering circuit is configured to use for each logical channel the ciphering mask of said channel.

13. The apparatus as claimed in claim 12, wherein the ciphering algorithm device is configured to use the direction of transmission as an additional input parameter.

14. The apparatus as claimed in claim 12, wherein the logical channel specific parameter is one of the following:

a Radio Access Bearer Identifier, a Logical Channel Identifier, or a Signaling Link Identifier.

15. The apparatus as claimed in claim 12, wherein the transport channel specific parameter is a Dedicated Channel Identifier.

16. The apparatus as claimed in claim 12, wherein the ciphering algorithm device is configured to use a radio frame specific parameter as an additional input parameter.

17. The apparatus as claimed in claim 16, wherein the radio frame specific parameter is a User Equipment Frame Number.

18. The apparatus as claimed in claimed in claim 12, wherein a Radio Link Control Layer Protocol Data Unit of at least one channel is already ciphered, and the ciphering circuit is configured not to cipher said already ciphered Radio Link Control Layer Protocol Data Unit.

19. The apparatus as claimed in claim 12, wherein the ciphering circuit is configured to accept plain data including at least two successive Radio Link Control Layer Protocol Data Units of one logical channel, and the ciphering algorithm device is configured to produce for said logical channel an individual ciphering mask and the ciphering circuit is configured to use for each Radio Link Control Layer Protocol Data Unit a different part of the ciphering mask.

20. The apparatus as claimed in claim 12, wherein the generator, the ciphering algorithm device, and the ciphering circuit reside in the Medium Access Control Layer of a protocol stack.

21. The apparatus, as claimed in claim 12, wherein the ciphering algorithm device is configured to produce a new ciphering mask for each radio frame of the physical layer of the protocol stack.

22. The apparatus, as claimed in claim 12, wherein the ciphering algorithm device is configured to produce a new ciphering mask for each interleaving period of the physical layer of the protocol stack.

23. A system comprising;

a generator configured to generate a ciphering key;

a ciphering algorithm device connected with the generator, said device configured to produce a ciphering mask using the ciphering key as an input parameter;

a ciphering circuit connected with the ciphering algorithm device, said circuit configured to produce ciphered data by applying the ciphering mask to plain data;

and the ciphering algorithm device being configured to use a logical channel identifying parameter or a transport channel identifying parameter as an additional input parameter,

wherein the ciphering circuit is configured to accept plain data including Radio Link Control Layer Protocol Data Units from at least two parallel logical channels for communication with one user equipment, and the ciphering algorithm device is configured to produce for each logical channel an individual ciphering mask and the ciphering circuit is configured to use for each logical channel the ciphering mask of said channel.

24. The system as claimed in claim 23, wherein the ciphering algorithm device is configured to use the direction of the transmission as an additional input parameter.

25. The system as claimed in claim 23, wherein the logical channel identifying parameter is one of the following;

a Radio Access Bearer Identifier, a Logical Channel Identifier, a Signaling Link Identifier.

26. The system as claimed in claim 23, wherein the transport channel identifying parameter is a Dedicated Channel Identifier.

27. The system as claimed in claim 23, wherein the ciphering algorithm device is configured to use a radio frame specific parameter as an additional input parameter.

28. The system as claimed in claim 27, wherein the radio frame specific parameter is a User Equipment Frame Number.

29. The system as claimed in claim 23, wherein a Radio Link Control Layer Protocol Data Unit of at least one logical channel is already ciphered, and the ciphering circuit is configured not to cipher said already ciphered Radio Link Control Layer Protocol Data Unit.

30. The system as claimed in claim 23, wherein the ciphering circuit is configured to accept plain data including a Radio Link Control Layer Protocol Data Unit from one logical channel, the ciphering algorithm device is configured to produce for said logical channel an individual ciphering mask, and the ciphering circuit is configured to use for said logical channel the ciphering mask of said channel.

31. The system as claimed in claim 23, wherein the ciphering circuit is configured to accept plain data including at least two successive Radio Link Control Layer Protocol Data Units of one logical channel, the ciphering algorithm device is configured to produce for said logical channel an individual ciphering mask, and the ciphering circuit is configured to use for each Radio Link Control Layer Protocol Data Unit a different part of the ciphering mask.

32. The system as claimed in claim 23, wherein the generator, the ciphering algorithm device, and the ciphering circuit reside in the Medium Access Control Layer of a protocol stack.

33. The system as claimed in claim 23, wherein the ciphering algorithm device is configured to produce a new ciphering mask for each radio frame of the physical layer of the protocol stack.

34. The system as claimed in claim 23, wherein the ciphering algorithm device is configured to produce a new ciphering mask for each interleaving period of the physical layer of the protocol stack.