In a notice to the ASX on Monday, the company said the agency would be using NC Protect "for secure, policy-based collaboration and sharing of sensitive information using a zero trust architecture".
This is the biggest sale through its Microsoft IP Co-Sell partnership.
The deal covers software licensing and support for five years.
"Tightly marketed and integrated into the Microsoft suite of collaboration tools, NC Protect enables agencies to enforce granular, zero trust-based security at the document level.
"The growing level of engagement we have with Microsoft field reps through the Microsoft IP Co-Sell program allows us to do more account mapping to identify joint opportunities and ensure customer success.”
archTIS acquired Nucleus Cyber in October last year.