WireGuard is an open-source VPN protocol, created by Jason A. Donenfeld and released in 2015, and it's the fastest one available today. It powers Fast mode in NymVPN, via a censorship-resistant fork called AmneziaWG, so you get WireGuard's speed plus resistance to VPN blocking.
Why it's so fast
Two reasons: a tiny codebase and modern cryptography. WireGuard is roughly 4,000 lines of code against OpenVPN's 100,000, which means less overhead, fewer places for bugs, and far easier auditing. In practice it can run upwards of 50% faster than OpenVPN. It's also stateless, so when your phone jumps from Wi-Fi to cellular it resumes instantly instead of renegotiating a session.
The cryptography inside
WireGuard uses a fixed, expert-reviewed set of primitives, with no ciphers to configure and so no room for misconfiguration:
- Noise protocol (Noise_IK) for the handshake, with perfect forward secrecy and protection against replay and key-compromise impersonation.
- Curve25519 for key exchange.
- ChaCha20-Poly1305 for encryption, typically faster than AES-GCM.
- BLAKE2 and SipHash24 for hashing.
Its one weakness, and how NymVPN fixes it
WireGuard has no built-in obfuscation: its packets have a recognizable signature that deep packet inspection can spot and block, which matters wherever VPNs are restricted. NymVPN's AmneziaWG fork sends decoy packets before the handshake to scramble that signature while keeping the speed. It's the default for all Fast mode traffic. More in the AmneziaWG announcement.
How NymVPN uses it differently
Most VPNs run WireGuard through one company-owned server, so a single party sees both who you are and what you do. NymVPN sends Fast-mode traffic through two independent nodes with an extra layer of encryption, so no node can link your identity to your activity. See How does NymVPN implement WireGuard?
Related questions
Is WireGuard secure?
Yes. Its primitives are considered unbreakable today, and its small open-source codebase has been audited extensively.
Which mode uses WireGuard?
Fast mode. Anonymous mode uses the Nym mixnet with the Sphinx packet format instead. See What's the difference between NymVPN Fast & Anonymous mode?