She said the Brussels attack that killed more than 30 people is the “latest brutal reminder” that more must be done to defeat Islamic State militants.

So far it has not been determined if the suspected terrorists in Brussels used encrypted devices to plan or communicate during the attacks.

“We do not know yet what role, if any, encrypted communications played in these attacks,” Rep. Adam Schiff(D-Calif.) said in a statement. “But we can be sure that terrorists will continue to use what they perceive to be the most secure means to plot their attacks,”

In December during a debate with rival Bernie SandersClinton characterized encryption as a “terrorist tool used in the Paris attacks.” She said the US should launch a “Manhattan-like project” to “bring the government and tech communities together” so that law enforcement can “prevent attacks.”

In February House Homeland Security Committee Chairman Michael McCaul, R-Texas, and Democratic Sen. Mark Warner of Virginia introduced a bill calling for a committee to examine encryption. Warner said the committee will be based on the 9/11 commission.

Manhattan District Attorney Cyrus Vance said a congressional committee on encryption should make recommendations within 90 days.

“It could set the table for congressional action but also for the next administration,” said Warner. ” We want to maintain American innovation, but we also need to maintain American security. Encryption is part of the fabric of American security. We also need to have ways we can go after criminals and terrorists.”

McCaul said apps like Telegram and Wire that provide end-to-end encryption pose a challenge to law enforcement. He said encrypted private communications is “probably the biggest challenge to law enforcement I have seen in my lifetime.”