Home Affairs Minister Peter Dutton says changes to national security laws giving authorities more power to access encrypted messages have been reaping dividends.
"It has played a role, and a very positive role, in a number of investigations," he told Nine's Today program on Wednesday.
Three men were arrested in Sydney on Tuesday over an alleged Islamic State-inspired plot to attack police stations, consulates and churches.
Mr Dutton would not say whether the encryption laws specifically helped in that case, stressing investigators would have used various approaches.
"Obviously when we've got 200 people who are involved in the investigation, there are many elements that would have brought this to fruition."
On Thursday, the government will introduce legislation banning any citizen suspected of extremism from returning to Australia for up to two years.
Labor has previously raised concerns the temporary exclusion orders could be unconstitutional.
Parliament's powerful intelligence and security committee has recommended the legislation be passed, subject to 18 changes.
Opposition home affairs spokeswoman Kristina Keneally said Labor was awaiting the government's response.
Ms Keneally said the government had not explicitly rejected a recommendation from the intelligence and security committee, which is chaired by Liberal MP Andrew Hastie, since 2013.
"We support the intent of the legislation which is to have appropriate mechanism in place to manage the return of these people to Australia."
