A pseudo-random code, also known as a pseudo-random sequence, is a determined sequence having fundamental characteristics similar to random sequences. Binary sequences are often widely used, so we are limited to studying binary sequences. A binary independent random sequence is generally called a Bernoulli sequence in probability theory and consists of two elements (symbols) 0, 1 or 1, -1. The values of the elements in different positions in the sequence are independent of each other. The probability of taking 0 is equal to 1/2: we refer to this series as a random series.

The existing anti-counterfeiting technologies mainly include seal anti-counterfeiting, mark anti-counterfeiting, two-dimensional code anti-counterfeit labels, etc. The common feature of these anti-counterfeiting methods is to establish a fixed or regular standard for the authenticity of the mark, multiple pieces, multiple times, multiple The result of continuous use of people, multi-person awareness, anti-counterfeiting technology and anti-counterfeiting technology is that more and more materials are produced for anti-counterfeiting labels, manufacturing is becoming more and more difficult, and identification technology is becoming more and more complex, often requiring special knowledge and specialization. The equipment can be accurately discriminated, the masses cannot grasp, and the effect of actual use is degraded. Moreover, there is the possibility that the inventor, designer, and producer of the anti-counterfeiting technology will falsify, and once the leak or imitation occurs, it is difficult to change the logo. It is costly and can hardly change for the logo in use. With the popularity of computer applications and the improvement of computer functions, the algorithms formed by fixed algorithms can be deciphered by algorithms, and once they are deciphered, they often cause huge losses.

A pseudo-random code is used for the password. In the classic cryptosystem, the encryption key is also the decryption key, which is called a single key system. In modern public key systems, each communicator has two keys, where the encryption key is public and the decryption key is strictly kept secret. Although humans have a long history of using various plain codes and passwords in communication, coding theory can be considered as a frontier in the 1950s after the rapid development of electronic technology and the specific needs of contemporary digital communication and digital storage. The new applied mathematics has a wealth of content.