Method and device for transmitting information with verification of unintentional and intentional transmission errors

• US 20070140259A1
• Filed: 12/22/2004
• Published: 06/21/2007
• Est. Priority Date: 12/23/2003
• Status: Active Grant

• Current Assignee: Cassidian SAS (Airbus SE)
• Original Assignee: EADS Secure Networks
• Inventors: Tenkes, Jean-Michel, Mouffron, Marc
• Granted Patent: US 7,774,677 B2
• Time in Patent Office: Days
• US Class Current: 370/395.320
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 2209/20 Manipulating the length of blocks of bits, e.g. padding or block truncation
• 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 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

For the transmission of information with verification of transmission errors, a useful information message (M) is transmitted in a determined frame while being associated with a determined number p of transmission error verification bits (CRC,S) also transmitted in the frame. In order to have an element allowing the verification of intentional errors, determined number p1 of the transmission error verification bits form a seal (S) obtained from a determined sealing function, where p1 is a number less than p. Application to radiocommunications equipment requiring the verification of the integrity and the authentication of the messages transmitted.

Claims

1. Method of transmitting information with verification of transmission errors, wherein a useful information message is transmitted in a determined frame while being associated with a determined number p of transmission error verification bits also transmitted in said determined frame, wherein a determined number p1 of said p transmission error verification bits form a seal obtained from the useful information message using a determined sealing function, where p1 is a number less than p, and wherein the p−

p1 remaining transmission error verification bits form a cyclic redundancy code calculated from the useful information message

2. Method according to claim 1 wherein the p1 transmission error verification bits are calculated at the MAC protocol layer, and are then delivered to a channel coder at the physical layer.

3. Method according to claim 1, wherein the seal is obtained by truncating to p1 the result of the sealing function which is obtained on a number of bits greater than p1

4. Method according to claim 3, wherein the sealing function is of Hash-MAC type with key, with a Hash function selected from the group comprising the MD5 function, the SHA-1 function, the SHA-256 function and sealing functions designed on the basis of a block encryption algorithm.

5. Method according to claim 1, wherein the results of the sealing function is obtained directly on p1 bits.

6. Method according to claim 5, wherein the sealing function comprises the combination of a pseudorandom generation function and of a non-linear coding function.

7. Device for transmitting information with verification of transmission errors, comprising:

means for transmitting in a determined frame a useful information message associated with a determined number p of transmission error verification bits also transmitted in said determined frame, and

mean for obtaining a seal from the useful information message using a determined sealing function, which seal forms a determined number p1 of said p transmission error verification bits, where p1 is a number less than p, the p−

p1 remaining bits forming a cyclic redundancy code calculated from the useful information message

8. Device according to claim 7, comprising means for calculating the p1 transmission error verification bits at the MAC protocol layer, as well as a channel coder to which said p1 bits are delivered at the physical layer.

9. Device according to claim 7, comprising means for obtaining the seal by truncating to p1 the result of the sealing function which is obtained on a number of bits greater than p1.

10. Device according to claim 9, wherein the sealing function is of Hash-MAC type with key, with a Hash function selected from the group comprising the MD5function, the SHA-1 function, the SHA-256 function and sealing functions designed on the basis of a block encryption algorithm.

11. Device according to claim 7, comprising means for obtaining the result of the sealing function directly on p1 bits.

12. Device according to claim 11, wherein the sealing function comprises the combination of a pseudorandom generation function and of a non-linear coding function.

13. Radiocommunications equipment comprising a device according to claim 7.