VPN (Virtual Private Network) is a technology that establishes a logical network layer over an existing physical infrastructure. It isolates user traffic from the public internet through encapsulation and encryption mechanisms, preventing unauthorized data interception or modification.
When a connection is initiated, the client and server negotiate authentication parameters and cryptographic keys. Data is wrapped into new packets (tunneling), where the original IP packet becomes the payload for the outer transport protocol. Common protocol stacks include IPsec, OpenVPN, and WireGuard.
VPN is utilized in the following scenarios:
- Connecting remote branch offices into a single corporate network (Site-to-Site);
- Providing secure remote access to internal company resources;
- Protecting traffic when using untrusted or public Wi-Fi networks.
Technical Implementation
Modern WireGuard implementations utilize ChaCha20 and Poly1305 cryptography. This allows for throughput levels close to the physical link speed with significantly lower latency and a smaller codebase compared to traditional OpenVPN or IPsec deployments.