encoding data hidden in a visual and machine-readable code

Abstract

The present invention relates to a method for encoding accessible and hidden data in the form of a machine-readable visual code. The visual code comprises a number X of graphic units UG(1), …UG(X) respectively positioned at positions P(1), …P(X) of the visual code, each graphic unit UG(i) having a graphic value VG(i). The method comprises: obtaining the values ​​v(1), …v(X) obtained by encoding the accessible data using a first type of encoding; determining ⌊X.λ⌋ positions P(a1), P(a2)….P(a⌊X.λ⌋) from among the positions P(1), …P(X); and encoding the hidden data into a number ⌊X.λ⌋ of values ​​v'(1), …v'(⌊X.λ⌋) obtained using a second type of encoding. encoding; Obtaining the visual code in which: VG(i) is representative of v(i) if P(i) is not one of the positions P(a1), P(a2)….P(a⌊ X.λ ⌋), VG(i) is representative of v'(j) if P(i) is the position P(aj). Figure for the abbreviation: Fig. 5

Claims

14. Visual code reading device comprising means for implementing the method according to claim 13.

15. A computer-readable data carrier comprising instructions which, when executed by a computer, cause the computer to implement the method according to claim 13.

16. Method for verifying the authenticity of a visual code comprising: - encoding the visual code on the basis of hidden data and accessible data according to the encoding method of any one of claims 1 to 10; - associating the hidden data with the accessible data in a database; - decoding the accessible data and transmitting the accessible data to the database; - decoding the hidden data according to the decoding method of claim 13 and transmitting the hidden data to the database; - comparing the transmitted hidden data with the data associated with the accessible data in the database; if the data are the same, the visual code is considered authentic.

17. Method for verifying the authenticity of a visual code comprising: - encoding the visual code on the basis of hidden and accessible data according to the encoding method of any one of claims 1 to 10; - associating the visual code with the accessible data in a database; - decoding the accessible data to the database; - transmitting the accessible data and the visual code to the database; - comparing the transmitted visual code with the visual code associated with the accessible data; if the codes are the same, the visual code is considered authentic. [Fig. 2] S120 S180 If 30 SiSO S14Û S'22 [Fig. 5] [Fig. 7] [Fig. 9]

Images