Post-Quantum Encryption May Become a Mandatory Feature of the VPN of the Future.
Cybersecurity experts warn that in approximately 10-20 years , quantum computers will have sufficient computing power to decipher common cryptographic methods like RSA and ECC—an event they call “Q-Day.” These encryption protocols are currently the gold standard in VPN technology, but when Q-Day arrives, they will no longer be sufficient.
Post-quantum encryption (or PQE), which uses complex mathematical problems that even quantum computers can’t solve, is your VPN provider’s answer to the threat of “Q-Day.” While “Q-Day” is still many years away, PQE is a VPN feature you can enable today to protect your data from hackers who could store your encrypted data until quantum computers become powerful enough to decrypt it.
NordVPN, ExpressVPN, Mullvad, and others let you instantly enable PQE with the click of a button. But is this promising encryption protocol necessary or worth investing in today? I’ll explain how it works, what it protects against, and which providers offer it, so you can decide for yourself.
How does post-quantum encryption (PQE) work?
When you connect to the internet through a VPN tunnel, your traffic data is essentially encrypted into an unreadable code that can only be decrypted with an encryption key. This key is then securely transmitted to your device via a VPN handshake. This prevents anyone without access to the encryption key, including your internet service provider, from obtaining useful information about your network traffic and data usage. However, this technology only works because hackers lack access to hardware capable of decrypting encrypted network data without the encryption key. Given the rapid advancement of quantum computing, security researchers predict that it will be powerful enough to completely decrypt your encrypted data without access to the key itself.
Q-Day isn’t just a distant threat. Attackers are already using “collect data now, decrypt later” (HNDL) attacks to store your encrypted network data and decrypt it once Q-Day arrives. This means they will suddenly gain access to years of sensitive user data once quantum computers gain sufficient computing power thanks to hardware improvements. That’s why, in August 2024, NIST standardized new encryption algorithms developed through a multi-year open competition. Three models were found to be sophisticated enough to withstand quantum computer attacks: ML-KEM (also known as Kyber) for key exchange, and ML-DSA and SLH-DSA for digital signatures.
If your work involves sensitive data, if you conduct a lot of high-value financial transactions, or if you work in a regulated industry with strict compliance requirements, PQE is worth considering. While its availability is limited to certain VPN providers and only within specific price ranges, security-conscious companies and professionals working in sensitive industries will find it genuinely useful, so it’s not just a marketing ploy.
VPN services that support post-quantum encryption
Many companies use the phrase “quantum-safe” in their marketing, but not all offer PQE as a standard VPN feature. Currently, NordVPN, ExpressVPN, and Mullvad are the three main providers that offer PQE as an optional feature on several plans.
NordVPN
In 2024, NordVPN implemented PQE technology in its Linux app, and later on for Windows, Android, and Apple operating systems. It runs on the NordLynx protocol with the ML-KEM algorithm layered on top of the existing Wireguard encryption. However, this also means you can’t use PQE with NordVPN if you’re using a dedicated IP address, meshnet, or the OpenVPN protocol.
Since PQE is available to all NordLynx users, it doesn’t require a premium subscription or additional service. All existing NordVPN customers can enable it, regardless of whether you’re on the Basic or Prime plan. Here’s how to do it if you’re already using NordVPN:
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On Windows: Open the NordVPN app, go to Settings > Connections . Enable Post-Quantum Encryption .
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On macOS: Open the app on your Mac. Go to “Preferences,” then the “General” tab, and turn on the “Post-Quantum Encryption” toggle.
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On iOS, Android, tvOS, or Android TV: Tap your profile icon. You’ll easily find the toggle for post-quantum encryption here.
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On Linux: Go to the terminal and run the following command: nordvpn set pq on.
ExpressVPN
Even before NIST standardization, ExpressVPN was one of the first companies to offer the Kyber algorithm through its Lightway protocol back in 2023. Following the standardization of the ML-KEM protocol, ExpressVPN upgraded its platform to closely align with NIST standards, introducing a number of improvements.
Interestingly, ExpressVPN enables PQE by default on all plans. However, this requires using the Lightway protocol, not an outdated alternative like OpenVPN. If you’re unsure whether PQE is enabled, here’s how to check:
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Open the ExpressVPN app.
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Make sure you have the latest version of the app.
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Click “Settings” . Go to the “Protocol” tab.
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Check if one of the following options is selected: Automatic , Lightway UDP , or Lightway TCP . If not, simply select any of them to enable PQE.
Mulvad
Mullvad introduced a pilot version of its post-quantum encryption key exchange protocol back in 2017, but the experimental implementation was replaced by a new version based on the classic McEliece algorithm, running on top of all existing WireGuard servers. With the launch of the 2023.3 desktop app, Mullvad introduced a fully stabilized PQE feature and expanded support for Android and iOS.
Mullvad doesn’t have feature-based pricing plans. Every paying customer has access to this feature without the need for additional purchases. It should be enabled by default on desktop computers unless you specifically opt out, but mobile apps require manual activation. You can do this by following these steps:
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On Windows, macOS, and Linux: Go to Settings > VPN Settings > WireGuard Settings . Make sure Quantum-resistant tunnel is enabled . Once the VPN is connected, you should see a green line of text: “QUANTUM-SECURE CONNECTION.”
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On Android and iOS: Launch the Mullvad VPN app. Go to Settings > VPN Settings . Find the “Quantum-Resistant Tunnel” option and enable it.
Does it make sense to use PQE right now?
Enabling post-quantum encryption has no downsides if your VPN provider already supports it as part of your current plan. I didn’t notice any significant reduction in latency or speed when testing this feature on NordVPN and ExpressVPN. But if you’re wondering whether switching plans or providers just for post-quantum encryption is worth it, the answer depends on your typical workflow.
Even by the most optimistic estimates, quantum computers are still far from being able to crack existing security protocols like RSA and ECC. However, HNDL attacks pose a significant security risk, so companies and individuals working in sensitive industries and handling confidential information should be aware of them. For routine web browsing workflows, quantum protection may be overkill. But when working with financial data, accessing medical portals, or sending sensitive information that cannot be intercepted, quantum protection provides additional assurance.