Unveiling the Security of New Train Ticket 2D Barcodes

A bar code is a mark consisting of a set of regularly arranged bars, spaces, and corresponding characters. “Bar” refers to a portion where the reflectance of light is low, and “empty” refers to a portion where the reflectance of light is relatively high. These bars and spaces are composed of The data expresses certain information and can be read by specific devices and converted into computer-compatible binary and decimal information. A one-dimensional bar code only expresses information in one direction (usually the horizontal direction), but does not express any information in the vertical direction, and its certain height is usually to facilitate the alignment of the reader. Barcodes for storing information in two-dimensional spaces in the horizontal and vertical directions are called 2-dimensional barcodes. The two-dimensional bar code can express information simultaneously in both horizontal and vertical directions, so it can express a large amount of information in a small area.

Two-dimensional bar code is to record data symbol information with a certain geometrical pattern in the plane (in the two-dimensional direction) according to a certain law. The code is used to skillfully use the "0" that constitutes the internal logic of the computer. The concept of "1" bit stream, using a number of geometric entities corresponding to binary to represent literal numerical information, automatic reading through image input device or photoelectric scanning device to achieve automatic processing of information: It has some common features of bar code technology. : Each code system has its own specific character set; each character occupies a certain width; it has a certain verification function. At the same time, it also has the features of automatic identification of different lines of information, and the ability to handle graphic rotation changes.

A one-dimensional bar code is usually an identification of an item, not a description of the item. That is, the bar code is only the code of the item to facilitate the scanning of the item. The bar code does not contain the description information of the product, and a background database is needed to support the scanning. One-dimensional bar codes are limited by their own information volume. For example, the data volume is small and can only contain letters and numbers; the bar code size is relatively large; the bar code cannot be read after being damaged. With the development of modern high-tech, there is an urgent need to use barcodes to represent more information in a limited geometric space to meet the ever-changing needs of information representation. In this way, 2D barcodes came into being.

Two-dimensional bar code has the superiority that one-dimensional bar code cannot match, compared to one-dimensional bar code:

1. Two-dimensional bar code information capacity, high information density, strong coding capabilities. It can encode small data files including photos, texts, fingerprints, palm prints, sounds, and signatures, and represent a large amount of information on a limited area.

2. Two-dimensional bar code can accurately describe the "article", the system gives the item a unique anti-counterfeit code and identifies it on the product or package. The product can be copied by the counterfeit but the code is unique, and it is convenient to realize the place away from the database and inconvenient networking. data collection;

3. The two-dimensional bar code is easy to print, the cost is very low, the error correction ability is strong, the decoding reliability is high, and the anti-counterfeit capability is extremely strong. It is precisely because the two-dimensional bar code can realize the two important functions of machine reading and anti-counterfeiting, so it is widely used in various card systems such as ID cards, driver's licenses, passports, and visas.

The new version of the train ticket upgrade anti-counterfeit can effectively suppress the use of fake tickets. It can be said that if manufacturers want to break through this technology, there is still a long way to go to make or sell fake tickets. However, whether the current situation of the Spring Festival travel ticket is difficult to obtain can still be improved. It takes time to prove it.