WireGuard is a free and open-source virtual private network (VPN) protocol that was designed to be fast, simple, and secure. It is a point-to-point VPN protocol that uses encryption to protect the data that is transmitted between the client and the server. WireGuard is very lightweight, with a small code base and low overhead, making it well-suited for use on embedded devices, such as routers and mobile phones.

WireGuard uses public key cryptography to authenticate users and establish secure connections. Each user is assigned a public and private key pair, and the server uses the public key to encrypt data that is sent to the client. The client then uses its private key to decrypt the data and process it. WireGuard uses the ChaCha20 encryption algorithm for data encryption, which is considered to be highly secure and efficient.