RTX Corporation's (NYSE: RTX) BBN Technologies has released Maude-HCS, an open-source toolkit for modeling and testing covert communication networks. The tool is funded by the Defense Advanced Research Projects Agency under its PWND2 program and is available on GitHub.

Maude-HCS enables cyber defense teams to validate hidden communication systems that embed covert messages into ordinary network traffic. The toolkit predicts system performance metrics including latency, data rate and detection avoidance duration with 1% to 9% error compared to controlled experimental deployments, according to the company.

"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.

The toolkit operates on standard computing hardware and scales log-linearly with model size to handle enterprise-scale traffic on a single eight-core server. The company states the tool can replace weeks of testing with automated analysis completed in hours.

Hidden communication systems are used by journalists and military forces to exchange information in environments where communications might be monitored or blocked. These systems aim to conceal both message content and the existence of communication itself.

RTX BBN Technologies, founded in 1948, focuses on advanced technology research for national security applications. RTX Corporation reported 2025 sales of more than $88 billion and employs over 180,000 people globally. The company is headquartered in Arlington, Virginia.

Research related to Maude-HCS is available as a pre-print on arXiv, according to the press release statement.