What's the use of a dongle?

 What's the use of a dongle?

What happens if you unplug the dongle plugged into the USB port of the computer?

Dongle is a kind of hardware device that looks like U disk. It is named encryption lock. Later, it has developed into a popular industry term of software protection. "Dongle" is a kind of encryption product which is inserted into the parallel port of computer and combines software and hardware (the new dongle also has USB port). Generally, there are dozens or hundreds of bytes of nonvolatile storage space for reading and writing, and now the newer dog also contains a single chip microcomputer. Software developers can exchange data with softdog through interface function (that is, read and write softdog) to check whether the softdog is inserted in the interface; Or directly use the tool attached to the softdog to encrypt your own EXE file (commonly known as "shell"). In this way, software developers can set multiple software locks in the software, and use the softdog as the key to open these locks; If the softdog is not inserted or does not correspond, the software will not run normally.

The encrypted dog exchanges data with the encrypted dog in the process of software execution to realize encryption. The embedded MCU circuit (also known as CPU) of the encrypted dog makes the encrypted dog have the processing ability of judgment and analysis, and enhances the active anti decryption ability. This kind of encryption product is called "intelligent" encryption dog. The built-in MCU of the encryption dog contains the algorithm software specially used for encryption. After the software is written into the MCU, it can no longer be read out. This ensures that the dongle hardware cannot be copied. At the same time, the encryption algorithm is unpredictable and irreversible. Encryption algorithm can transform a number or character into an integer, such as dogconvert (1) = 12345, dogconvert (a) = 43565.

Dongle is an intelligent software protection tool for software developers. It includes a set of hardware installed on the computer parallel port or USB port, and a set of interface software and tool software suitable for various languages. Based on hardware protection technology, the purpose of dongle is to prevent intellectual property from being used illegally by protecting software and data.

In fact, from the perspective of programming, a. Key file is added to a small storage tool. In this way, you need to access key before you can access something