Method for encoding and decoding communication data

• US 20040202323A1
• Filed: 02/18/2004
• Published: 10/14/2004
• Est. Priority Date: 08/30/2001
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Fellerer, Josef
• Granted Patent: US 7,383,435 B2
• Time in Patent Office: Days
• US Class Current: 380/44
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/16 the keys or algorithms being changed during operation

Abstract

The invention relates to a method for encoding and decoding communication data, especially voice data, which is transmitted in a plurality of data packets in a digital communication network, especially for internet telephony. The communication data is encoded by means of a selected code at an emission point in each of the data packets; a code number of the selected code is transmitted as code information with each of the data packets; and the communication data is decoded by allocating the code number to the code stored in the code table created at a reception point.

Claims

1. A method for encrypting and decrypting communication data transmitted in a plurality of data packets in a digital communication network, comprising:

encrypting the communication data in each of the data packets with a selected key at a send location;

transmitting a key number of the selected key with each of the data packets as key information; and

decrypting the communication data by assignment of the key number to the key stored in a key table set up at a receive location.

2. A method according to claim 1, wherein the key is selected by defining the key number as a random number by a random number generator.

3. A method according to claim 1, wherein there is access to key tables with identical content at the send location and the receive location.

4. A method according to claim 1, wherein size information about the extent of the communication data is transmitted with one of the data packets.

5. A method according to claim 1, wherein the key is an algorithm in accordance with the Data Encryption Standard and/or in accordance with the Advanced Encryption Standard.

6. A method according to claim 1, wherein the communication data is transmitted as payload data by the User Datagram Protocol transport protocol and additional data is transmitted by the Real Time Protocol in a header assigned to each of the data packets.

7. A method according to claim 1, wherein the communication data is encrypted and decrypted within a telecommunication system connected to a plurality of terminals.

8. A method in accordance with claim 1, wherein Encryption information about an encryption algorithm used is transmitted in a data packet.

9. A Method according to claim 1, wherein the communication data is speech data.

10. A method according to claim 2, wherein there is access to key tables with identical content at the send location and the receive location.

11. A method according to claim 2, wherein size information about the extent of the communication data is transmitted with one of the data packets.

12. A method according to claim 3, wherein size information about the extent of the communication data is transmitted with one of the data packets.

13. A method according to claim 2, wherein the key is embodied as an algorithm in accordance with the Data Encryption Standard and/or in accordance with the Advanced Encryption Standard.

14. A method according to claim 3, wherein the key is an algorithm in accordance with the Data Encryption Standard and/or in accordance with the Advanced Encryption Standard.

15. A method according to claim 2, wherein the communication data is transmitted as payload data by the User Datagram Protocol transport protocol and additional is transmitted by the Real Time Protocol in a header assigned to each of the data packets.

16. A method according to claim 2, wherein the communication data is encrypted and decrypted within a telecommunication system connected to a plurality of terminals.

17. A method in accordance with claim 2, wherein Encryption information about an encryption algorithm used is transmitted in a data packet.

18. A method according to claim 1, wherein the communication data is Internet telephony.

19. A method according to claim 6, wherein the additional data is the type of payload data and/or the time at which the payload data was created.

20. A method according to claim 15, wherein the additional data is the type of payload data and/or the time at which the payload data was created.