What is OpenBoundary technology?

OpenBoundary is a new technology developed by ExpressVPN that enables network operators to restrict access to verified criminal domains safely and transparently.

How does OpenBoundary block access to illegal material?

OpenBoundary is a straightforward DNS control used to block access to known child sexual abuse material sites without breaking encryption or inspecting traffic.

Will OpenBoundary compromise user privacy?

ExpressVPN states that OpenBoundary is designed to act without weakening the privacy protections millions of people rely on, by implementing clear boundaries and careful engineering.

Home / Technology / VPN Tech Blocks Child Abuse Sites Transparently

VPN Tech Blocks Child Abuse Sites Transparently

5 Mar

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Summary

ExpressVPN's new OpenBoundary technology restricts access to criminal domains.
The tool blocks identified child sexual abuse material sites transparently.
OpenBoundary is an open-source tool available for adoption by others.

VPN Tech Blocks Child Abuse Sites Transparently

ExpressVPN, in collaboration with the Internet Watch Foundation (IWF), has developed a new technology named OpenBoundary. This innovation enables network operators to restrict access to verified criminal domains in a safe and transparent manner. As of March 5, 2026, OpenBoundary is designed to block access to all identified child sexual abuse material (CSAM) domains verified by the IWF.

ExpressVPN will implement OpenBoundary across its services, including CyberGhost VPN and Private Internet Access. The company is also making this technology open-source, encouraging other VPN providers, Internet Service Providers (ISPs), and cloud platforms to adopt similar safeguards. This move aims to elevate industry standards for privacy-preserving infrastructure.