A statement from the company said the agreement came after a successful beta program was run by the department, among others.
The deal is for 12 months and two additional annual extensions, with a minimum of 50 users and the ability to add more users as needed.
archTIS said the initial group of 50 users would generate annual revenue of $30,000, but the number of users was expected to grow as the AG's department has about 1400 staff both in Australia and abroad.
"Securing such a high-profile organisation clearly demonstrates the utility of our platform in enhancing the security of sensitive information.
"Any organisation concerned about protecting the security of their information is a potential archTIS customer.
"We are excited by the potential commercial opportunity available to us and look forward to accelerating our rate of customer acquisition and making more announcements like this in the near future."