Everything to Know About VPN Encryption

A virtual private network, or VPN, allows internet users to mask or hide specific information through encryption, keeping their browsing more secure. VPNs also modify your IP address to allow access to websites that may be blocked by an entity, such as the government or a business.

VPN encryption is the key to its security. Our VPN usage survey found that only 39% of Americans actively use a VPN — yet security on public Wi-Fi is the number one reason people want one. If you are using a VPN or looking for a solution, understanding the types of encryption and protocols available will help you decide on the best one for your needs.

Does a VPN encrypt data?

A virtual private network (VPN) encrypts your data, making it unreadable to anyone trying to spy on you. Using shared Wi-Fi, like at a coffee shop or hotel, or even your home network with your internet service provider (ISP) watching your activity, puts you at risk of prying eyes.

Encryption takes information, such as your browsing data, and hides it in a series of codes to mask its true meaning. VPN encryption can help protect your personal information when using public Wi-Fi. Beyond encryption, VPN services also offer additional security features to protect your internet activity.

What does a VPN hide?

VPNs are useful tools for many different reasons. You might need a VPN to hide your IP address, your location, or your browser history:

• Your IP address: A VPN changes your IP address and gives you a new one while the VPN is active. Your IP address reveals your online activity, so hiding it with a VPN prevents anyone from tracking you.
• Your location: Information about your location is also shared when you're browsing online. If you're traveling internationally and want to access U.S.-based sites, a VPN can provide a regional IP address based on server availability.
• Your browser history: When connected to a VPN, your browsing history is encrypted and inaccessible by your internet service provider (ISP), hackers, and other entities. This can protect your personal information when using a public internet connection. Features such as incognito mode do not fully hide your IP address and browser history.

By hiding these things, a VPN protects personal information that may be vulnerable to online hackers.

Do VPNs really work?

VPNs protect your online security. Their effectiveness depends on the security protocol and the type of encryption used. As technology evolves, so do the different protocols for VPN security.

How do VPNs encrypt data?

VPNs use several different types of encryption to protect your data. The difference in encryption is mainly based on the encryption key used. Many encryption methods include the Advanced Encryption Standard (AES), public-key, symmetric, and Transport Layer Security (TLS).

AES encryption

AES encryption is one of the strongest available encryption methods. Three different key lengths — AES-128, AES-192, and AES-256 — provide increasing levels of security. AES-256 is the standard used by the U.S. government and is the most widely used option among reputable VPN providers. Despite its strength, AES uses less memory than many other encryption methods and is efficient to implement.

Public-key encryption

Public-key encryption uses a combination of two keys — a public key and a private key. In order to decrypt any data, you must have both keys. This type of encryption is often used in Secure Sockets Layer (SSL), which encrypts data transmitted over websites. A website with SSL security will display an HTTPS prefix instead of HTTP. Public-key encryption is also known as asymmetric encryption.

Symmetric encryption

Symmetric encryption uses the same key to encrypt and decrypt information. The data is scrambled during encryption and unscrambled once the recipient inputs the correct key. AES is a symmetric encryption algorithm. Because both parties must share the same key, there is concern that it could be intercepted during exchange, which is why it is typically combined with public-key encryption in practice.

Transport Layer Security (TLS)

TLS is an encryption protocol that protects data transmitted over the internet. It is used primarily to protect communication between websites and servers, but it also protects email, messaging, and other communications. TLS covers three functions: encrypting the data, authenticating that the correct recipient is receiving it, and verifying that the data hasn't been tampered with in transit. VPNs use TLS as part of their broader security architecture.

VPN encryption method	Security strength
AES	Strongest
Public-key	Strong
Transport Layer Security (TLS)	Strong
Symmetric	Weakest standalone; typically combined with public-key encryption

Types of VPN protocols

One of the things that makes VPNs different is the protocol they use. These protocols have varying levels of security, may use more or less bandwidth to encrypt your data, and may be outdated or unsupported by some providers. Understanding VPN protocols and which ones are best for your situation is important for your online security.

WireGuard

WireGuard is now the leading modern VPN protocol and the default choice for most top VPN providers, including NordVPN (via NordLynx), Surfshark, and ExpressVPN. It uses an open-source codebase that delivers faster speeds and lower data overhead than older protocols, without compromising security. WireGuard is thoroughly audited and widely trusted. For most users, it's the best option available.

IKEv2/IPSec

The Internet Key Exchange version 2 (IKEv2) paired with IPSec is a reliable, fast protocol, particularly well-suited to mobile devices. It handles network switching smoothly — for example, moving from Wi-Fi to cellular — without dropping the VPN connection. It offers strong encryption and low bandwidth overhead. Compatibility is broad across Windows, macOS, iOS, and Android.

OpenVPN

OpenVPN is a widely used, thoroughly audited, open-source protocol. It offers strong security and is highly customizable. OpenVPN is available in two modes: UDP (faster, better for streaming and gaming) and TCP (more reliable, better for restrictive networks). The main trade-off is that it uses more data overhead than WireGuard and can be more complex to configure manually.

L2TP/IPsec

Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol that, on its own, provides no encryption — it relies on IPSec to handle that. While it's available on many systems, it's slower than modern alternatives, can struggle with firewalls, and has been flagged as potentially compromised. It's largely been superseded by WireGuard and IKEv2 and is not recommended for new setups.

SSTP

SSTP is a Microsoft-owned protocol supported natively on Windows. It uses AES-256 encryption and can bypass many firewalls. However, because it's proprietary and closed-source, it cannot be independently audited for security vulnerabilities, which limits how much trust can be placed in it. Most users will be better served by WireGuard or OpenVPN.

PPTP

The Point-to-Point Tunneling Protocol (PPTP) was one of the first VPN protocols and is now considered cryptographically broken. It uses weak encryption, has known security vulnerabilities, and is commonly blocked by firewalls. PPTP should not be used for any situation where security matters, regardless of its speed or compatibility advantages.

VPN protocol	Security strength
WireGuard	Very strong — recommended for most users
IKEv2/IPSec	Very strong — best for mobile
OpenVPN	Very strong — widely supported
L2TP/IPsec	Moderate — largely superseded
SSTP	Strong but not independently auditable
PPTP	Not secure — do not use

Does a VPN protect you from hackers?

A major benefit of a VPN is that it protects your data from hackers, especially on public networks. Our public Wi-Fi survey found that 69% of internet users connect to public Wi-Fi at least once a week, and nearly half have connected to a network without verifying its legitimacy — a significant risk given how easily hackers can intercept traffic on unsecured networks.

For instance, if you're using unprotected Wi-Fi in a coffee shop and you check your bank account balance, a hacker may be able to infiltrate the network and gain access to your login information. A VPN scrambles and encrypts that data so that anyone intercepting the connection cannot read it. For more on staying safe on shared networks, see our guide on whether a VPN protects you on public Wi-Fi.

Can a VPN be traced?

Tracing a VPN depends on its type and the security standards offered. If you are using a high-quality VPN with a verified no-logs policy, your activity cannot be traced — even your ISP can only see that encrypted data is passing through its servers, not what that data contains.

If your VPN connection drops, your ISP immediately regains visibility into your activity. This is why a kill switch is an important feature — it automatically cuts your internet connection if the VPN drops, preventing any unencrypted data from leaking until the connection is restored.

If you use a premium VPN with obfuscated servers, even the fact that you're using a VPN will be hidden from your ISP and other observers.

What's the most secure VPN?

When looking for a secure VPN provider, you want to find one with a trusted encryption method, a modern protocol, and a verified no-logs policy. Here are some of our top-tested options:

VPN	Lowest price	Encryption method	VPN protocol
NordVPN	$3.09/mo	AES-256-GCM	OpenVPN, NordLynx (WireGuard), IKEv2/IPSec
Surfshark	$1.78/mo	AES-256-GCM	OpenVPN, WireGuard, IKEv2
ExpressVPN	$4.99/mo	AES-256	Lightway, OpenVPN, IKEv2, WireGuard
Proton VPN	$2.99/mo	AES-256 and ChaCha20	WireGuard, OpenVPN, IKEv2/IPsec, Stealth

What to look for in a secure VPN

To find the VPN that's best for you, make sure it has the features that matter most for your security. Here are the key things to look for:

• Encryption method: Look for AES-256 or AES-256-GCM, the government-standard encryption used by the most reputable VPN providers.
• VPN protocol: Prioritize providers that support WireGuard or IKEv2 as their default. Most paid VPNs use sufficient protocols, but some free VPNs rely on outdated or insecure options.
• No-logs policy: A VPN can have excellent encryption but still compromise your privacy if it logs and retains records of your activity. Look for providers with independently audited no-logs policies.
• Kill switch: Automatically cuts your internet connection if the VPN drops, preventing unencrypted data from leaking. Essential for anyone handling sensitive information.
• Extra features: Many providers also include threat protection, dark web monitoring, obfuscated servers, and split tunneling — useful additions depending on your needs.

The right VPN depends on your activities. Our study found that the majority of VPN users (84%) need a VPN to increase security while using public Wi-Fi, and nearly the same percentage (83%) say they use VPNs for general increased internet safety, underscoring the need for a trustworthy VPN service.

Bottom line

VPNs are effective tools for keeping data secure on shared networks, protecting your browsing history from your ISP, and bypassing content restrictions when traveling. Their effectiveness depends on the encryption method and protocol in use — AES-256 encryption paired with WireGuard or IKEv2 offers the strongest protection for most users.

When choosing one of the best VPNs available, look beyond the price and prioritize providers with independently audited no-logs policies, modern protocols, and a kill switch.  

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