The product key is the proof of product authorization, and it is a random number generated according to a certain algorithm (such as elliptic algorithm).

When the user inputs the key, the product will judge whether it conforms to the corresponding algorithm according to the key input, thus confirming the user's identity and usage rights.

Public key encryption technology uses a pair of matching keys to encrypt and decrypt. Each key performs one-way data processing, and the function of each key is just the opposite of the other. When one key is used for encryption, the other key is used for decryption. ?

The public key is made public by its owner, while the private key must be kept secret. In order to send a confidential message, the sender must use the public key of the receiver to encrypt the data. Once encrypted, only the receiver can decrypt it with his own private key. ?

Extended data:

How to check the product key of win 10;

1. Press "win+R" to open the "Run" program and enter "regedit?" In the input box. Enter to open the registry editor.

2. Then expand HKEY_LOCAL_MACHINE, SOFTWARE, Microsoft, Windows NT, CurrentVersion and SoftwareProtectionPlatform in the left directory.

3. Then double-click on the right side of SoftwareProtectionPlatform to open the registry "BackupProductKeyDefault", and you can see the key of win 10 system.

Baidu Encyclopedia-Product Key