Strong VPN encryption and security explained

VPN encryption is complex, relying on well-tested implementation of advanced mathematics. Read on to learn how ExpressVPN uses strong encryption to keep your data and communications safe.

Laptop showing encrypted text.

Video: How VPNs use tunneling and encryption

How VPNs use tunneling and encryption

How secure is ExpressVPN encryption?

Besides hiding your IP address and mixing your traffic with that of other users, ExpressVPN also encrypts your traffic between secure VPN servers and your computer. This keeps your data safe from being read by third parties.

ExpressVPN uses AES (Advanced Encryption Standard) with 256-bit keys—also known as AES-256. It’s the same encryption standard adopted by the U.S. government and trusted by security experts worldwide to protect classified information.

Lamp showing encrypted text.

256-bit keys means 2^256 or 1.1 x 10^77 possible combinations. That’s 115,​792,​089,​237,​316,​195,​423,​570,​985,​008,​687,​907,​853,​269,​984,​665,​640,​560,​000,​000,​000,​000,​000,​000,​000,​000 combinations! A brute-force attack on a 256-bit keyspace is simply infeasible, even if all the world’s most powerful supercomputers ran for as long as the universe has existed so far, billions and billions of times over.

VPN protocols: Lightway

ExpressVPN offers a variety of VPN protocols to implement strong and safe encryption between your computer and the VPN server location you connect to. When you use the ExpressVPN app, you can easily switch between the protocols, although it’s recommended that you choose the automatic setting, which will select the protocol optimal for your speed and security.

Speech bubbles with different VPN protocols.

In addition to offering a standard set of protocols, including OpenVPN and IKEv2, ExpressVPN built Lightway to outdo them all in speed, reliability, and security. Give it a try to see for yourself. Learn more about Lightway.

Here are some of the features of ExpressVPN encryption with Lightway:

Server authentication

Like HTTPS and OpenVPN, Lightway uses certificates to protect the user against man-in-the-middle attacks. Your VPN client has a certificate preloaded that is used to authenticate a VPN server.When using an external or open-source Lightway client, you will be able to load this certificate yourself to connect with VPN servers.

The two ciphers used in Lightway are AES-256-GCM and ChaCha20/Poly1305. Owing to the excellent hardware acceleration of AES available in most devices, Lightway will mostly default to this well-proven cipher. Only on lower-powered routers or entry-level mobile devices might ChaCha20 be used.

HMAC authentication

HMAC stands for keyed-Hash Message Authentication Code. This code protects the data from being altered in transit by an attacker who has the ability to read the data in real time. TLS and OpenVPN also use hashes for authentication, hence the H in HMAC.

Control-channel encryption

To ensure the integrity and confidentiality of encrypted data even on low-powered hardware, ExpressVPN uses AES-256-GCM. AES is one of the most widely used symmetric encryption standards. The 256 refers to the fixed size of each encrypted block, 256 bits. GCM (Galois/Counter Mode) allows your computer to encrypt multiple packages at once, ensuring that your connection never hangs even for a short moment.

Data-channel encryption

Data-channel encryption protects against your information being visible to the parties that your data travels through. ExpressVPN uses a symmetric encryption scheme, in which the key is negotiated using the elliptic curve Diffie-Hellman key exchange. The ExpressVPN server and your VPN app use clever mathematics to negotiate and verify a secret key that is then used to encrypt the data for the entire session.

Post-quantum protection

By integrating post-quantum support with DTLS 1.3, we are fortifying our VPN service to remain secure in the face of quantum computing advancements.

Lightway includes post-quantum protection by default, shielding you against attackers with access to both classical and quantum computers. ExpressVPN is one of the earliest VPNs to deploy post-quantum support, future-proofing our users for a quantum-safe world.

Download ExpressVPN on all your devices

A single ExpressVPN subscription lets you download a VPN for every popular platform. Need a VPN for multiple devices? Set up ExpressVPN on everything you own, and use it on eight at the same time.

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Frequently asked questions

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