Two-Dimensional Code Authenticating Device, Two-Dimensional Code Generating Device, Two-Dimensional Code Authenticating Method, and Program

摘要

A two-dimensional code authenticating device reads a self-authentication two-dimensional code to obtain an RS bit string, and detects a bit string c′ as an error using the RS bit string. Next, an exclusive OR between a bit string l included in the RS bit string and the bit string c′ detected as an error is calculated to obtain a bit string c′, and a bit string md is obtained by decrypting the bit string c′ through a scheme corresponding to the encryption. Subsequently, it is determined whether or not the decrypted bit string md matches the bit string m included in the RS bit string, thereby authenticating the self-authentication two-dimensional code.

主权项

1. A two-dimensional code authenticating device for authenticating a two-dimensional code comprising an information area expressing predetermined information by a distribution pattern of cells, and a correction area expressing correcting information for correcting an error by a distribution pattern of cells, the two-dimensional code authenticating device comprising:
two-dimensional code reading means for reading the two-dimensional code having a portion of the correction area replaced with an exclusive OR between a first correction bit string generated from the portion and a second correction bit string generated from a different portion of the correction area to obtain the correcting information; error detecting means for detecting the exclusive OR between the first correction bit string and the second correction bit string as an error using the correcting information obtained by the two-dimensional code reading means; and two-dimensional code authenticating means for authenticating the two-dimensional code by determining whether or not an exclusive OR between the first correction bit string included in the correcting information and the error detected by the error detecting means matches the second correction bit string included in the correcting information.