Reverse engineering (also known as reverse technology) is a process of product design technology reproduction, that is, to conduct reverse analysis and research on a target product, so as to deduce and obtain the design elements of the product such as processing flow, organizational structure, functional characteristics and technical specifications, so as to produce products with similar functions but not identical. Reverse engineering originates from hardware analysis in commercial and military fields. Its main purpose is to derive the design principle of the product directly from the analysis of the finished product without easily obtaining the necessary production information.
　　Reverse engineering may be mistaken for serious infringement of intellectual property, but in practical application, it may protect the owner of intellectual property. For example, in the field of integrated circuits, if a company is suspected of infringing intellectual property rights, reverse engineering technology can be used to find evidence.
　　The reasons for reverse engineering are as follows:
　　1. Interface design. Due to interoperability, reverse engineering is used to find out the cooperation agreement between systems.
　　2. Military or commercial secrets. Steal the latest research or product prototype of the enemy or competitor.
　　3. Improve the document. When the original documents are inadequate, and when the system is updated and the original designer is not available, reverse engineering is used to obtain the required data to supplement or understand the latest status of the system.
　　4. Software upgrade or update. Reverse engineering is used to understand existing or legacy software systems in order to evaluate the work required to update or migrate the system due to functional, compliance, security and other requirements changes.
　　5. Make unauthorized/unauthorized copies.
　　6. Academic/learning purpose.
　　7. Remove replication protection and camouflaged login permissions.
　　8. File loss: When reverse engineering is adopted, the file of a special equipment has been lost (or not at all), and the person in charge of the project cannot be found. The complete system often needs to be redesigned based on the old system, which means that the only way to integrate the original functions for the project is to use the reverse engineering method to analyze the existing fragments for redesign.
　　9. Product analysis: used to investigate the operation mode of the product, component composition, estimate the budget, and identify potential infringement.