Method for Communicating Between a Reader and a Wireless Identification Marker, Associated Reader and Marker

• US 20080185434A1
• Filed: 03/30/2006
• Published: 08/07/2008
• Est. Priority Date: 04/15/2005
• Status: Active Grant

• Current Assignee: IDEMIA Identity and Security France SAS (Advent International Corporation)
• Original Assignee: Sagem Defense Securite (Safran SA)
• Inventors: Chabanne, Herve
• Granted Patent: US 7,942,324 B2
• Time in Patent Office: Days
• US Class Current: 235/439
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/0858 Details about key distillation or coding, e.g. reconciliation, error correction, privacy amplification, polarisation coding or phase coding

Abstract

A method includes transmitting a first digital channel (X₀) from a reader to a marker, receiving a second digital channel (Y₀) corresponding to the first digital channel and to errors introduced by a noisy channel, introducing artificial errors into at least one of the first or second digital channels, carrying out an advantage distillation phase in such a way that a new first digital channel (X₁) is determined for the reader. A new second digital channel (Y₁) is determined for the marker such that the advantage is taken with respect to a possible passive attacker. In an information reconciliation phase, an error-correcting protocol is applied to the new first (X₂) and new second (Y₂) digital channel, and in carrying out a secrecy amplification phase, a hash function (G) is applied to the new first (X₂*) and the new second (Y₂*) digital channel.

Claims

1. A method for communicating between a wireless identification reader and a wireless identification marker via a noisy channel, comprising:

/a/ the transmission of a first numeric string from the reader to the marker;

/b/ the reception, on the marker, of a second numeric string corresponding to the first numeric string, excepting errors introduced by the noisy channel;

/c/ the introduction of artificial errors into at least one of the first and second numeric strings;

/d/ an advantage distillation phase in which a new first numeric string is determined on the reader on the basis of the first numeric string, and a new second numeric string is determined on the marker on the basis of the second numeric string, in such a way as to take the advantage with respect to a possible passive attacker;

/e/ an information reconciliation phase, wherein an error-correction protocol is applied to the new first and the new second numeric string in such a way that, at the end of step /e/, the new first and the new second numeric string are identical with a predetermined probability level; and

/f/ a secrecy amplification phase, wherein a hash function is applied to the new first and the new second numeric string.

2. The method as claimed in claim 1, in which the advantage distillation phase comprises the following steps:

the first and second numeric string are divided up into groups of N successive numerical values, where N is an integer;

an exclusive OR is carried out on each of said groups;

the results of the exclusive OR are exchanged between the reader and the marker;

the new first numeric string is determined on the reader on the basis of the first numerical value of each group of the first numeric string for which the result of the exclusive OR is identical to the result of the exclusive OR carried out on the corresponding group of the second numeric string; and

the new second numeric string is determined on the marker on the basis of the first numerical value of each group of the second numeric string for which the result of the exclusive OR is identical to the result of the exclusive OR carried out on the corresponding group of the first numeric string.

3. The method as claimed in claim 1, in which the introduction of artificial errors in step /c/ comprises a random modification of numerical values of at least one of the first and the second numeric string.

4. The method as claimed in claim 1, in which step /d/ is repeated a number of times depending on the estimated noise of the noisy channel.

5. The method as claimed in claim 1, in which the error-correction protocol is chosen in such a way as to allow a minimum of information to be leaked to a possible passive attacker.

6. A wireless identification reader suitable for communicating with a wireless identification marker via a noisy channel, comprising:

means for transmitting a first numeric string to the marker;

means for introducing artificial errors into the first numeric string;

means for determining a new first numeric string on the basis of the first numeric string, in such a way as to take the advantage with respect to a possible passive attacker;

means for applying an error-correction protocol to the new first numeric string; and

means for applying a hash function to the new first numeric string.

7. A wireless identification marker suitable for communicating with a wireless identification reader via a noisy channel, comprising:

means for receiving a second numeric string corresponding to a first numeric string transmitted by the reader, excepting errors introduced by the noisy channel;

means for introducing artificial errors into the second numeric string;

means for determining a new second numeric string on the basis of the second numeric string, in such a way as to take the advantage with respect to a possible passive attacker;

means for applying an error-correction protocol to the new second numeric string; and

means for applying a hash function to the new second numeric string.