RTX's BBN Technologies launches open-source tool to validate covert cyber networks

DARPA-funded Maude-HCS rapidly validates hidden communications

CAMBRIDGE, Mass., April 1, 2026 /PRNewswire/ -- RTX's (NYSE: RTX) BBN Technologies has released Maude-HCS, an open-source toolkit that enables cyber defense teams to model, test and validate covert communication networks. Funded by the Defense Advanced Research Projects Agency (DARPA) under its PWND2 program, the toolkit is available on GitHub and provides fast, reliable and scalable performance, allowing teams to accelerate innovation, validate designs and deploy in real-world environments.  

"Maude-HCS provides users a rigorous yet practical way to validate performance-privacy guarantees of hidden communication designs before they ever touch the wire," said Dr. Joud Khoury, principal investigator at RTX BBN Technologies. "This capability has the potential to fundamentally change how the national security community builds and validates covert communication channels."

Why covert communication networks matter

Hidden communication systems embed covert messages into ordinary network activity with the goal of concealing not only the content of the communication but also its very existence, so an observer sees only routine traffic. These systems are critical to both internet freedom and national security efforts, enabling journalists and U.S. armed forces, for example, to exchange information safely in high-risk or contested environments where overt communications might be monitored or blocked. Since the detection of a hidden channel can endanger lives and compromise missions, it is essential to ensure these systems remain both effective and undetectable.

How Maude-HCS solves the problem

• Provides rigorous guarantees on performance, scalability and privacy: predicts latency, data rate and how long the system can operate without being detected, with just 1% to 9% error compared with a controlled experimental deployment — confirming that the channel meets mission requirements while remaining invisible.
• Accelerates validation: replaces weeks of trial-and-error testing with automated analysis that delivers results in hours.
• Operates on standard computing hardware: scales log-linearly with model size, including the number of messages exchanged in the network, to handle enterprise-scale traffic on a single eight-core server.
• Enables open‑source collaboration: allows universities, industry partners and government labs to reproduce results and extend the toolkit, reducing development cycles from months to days.

By delivering measurable, verifiable pre-deployment performance, Maude-HCS strengthens U.S. cyber defense, protects critical infrastructure and maintains operational advantage in contested environments.

Research related to Maude-HCS is available as a pre-print on arXiv. 

About RTX BBN Technologies
Founded in 1948, RTX BBN Technologies provides advanced technology research and development with a focus on national security priorities. From the ARPANET to the first email, through the first metro network protected by quantum cryptography, BBN consistently transitions advanced research to produce innovative solutions for its customers. BBN takes risks and challenges conventions to create solutions in analytics and machine intelligence, non-kinetic domains, intelligent software and systems, and physical sciences.

About RTX
With more than 180,000 global employees, we push the limits of technology and science to redefine how we connect and protect our world. With industry-leading capabilities, we advance aviation, engineer integrated defense systems for operational success, and develop next-generation technology solutions and manufacturing to help global customers address their most critical challenges. The company, with 2025 sales of more than $88 billion, is headquartered in Arlington, Virginia.

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SOURCE RTX