(Adds Schiff comments, background)
By Patricia Zengerle and Dustin Volz
WASHINGTON, Nov 17 (Reuters) - U.S. lawmakers said on Tuesday it was likely that new, difficult to break "end-to-end" encryption technologies were used by individuals in Belgium, France and Syria involved in the Paris attacks last week.
"We can't tell you today specifically that they were using a specific encrypted platform. We think that's a likely communication tool because we didn't pick up any direct communication (before the attacks)," said Republican Senator Richard Burr, chairman of the Senate Intelligence Committee.
Hawkish lawmakers like Burr, and a number of intelligence officials, seized on the Paris attacks this weekend to argue that they illustrate the dangers of increasing encryption.
"I think it's safe to say that there are 30 end-to-end encrypted software packages that you can download for free. And, given the fact that between iTunes and PlayStation, the number of apps that are added on a weekly and monthly, yearly basis, and I think we anticipate that everything from this point forward will have an encrypted communications to it," he said.
"Now's the time for us to act," Burr said.
He said the committee was far from developing legislation to address the issue, and that it was trying determine the options that are available and then would decide the best course, short, medium and long-term.
Adam Schiff, the ranking Democrat on the House of Representatives Intelligence Committee, said he would not be surprised if it were ultimately shown that encrypted communications had been used by the perpetrators of the Paris attacks.
"We know that ISIS instructs their operatives to move from social media, once they're recruited people, to those applications where they can encrypt," Schiff said on cable network CNN.
Intelligence agencies have long warned that the rise of encrypted email, chat and phone platforms has made it more difficult to track suspicious activity. Senior Obama administration officials have pushed to allow for so-called "backdoors" that would give intelligence agents a way to access encrypted communications.
Privacy advocates, technology companies and security researchers generally oppose such vulnerabilities, warning that any weakness built in for law enforcement could also expose information to foreign nation states and malicious hackers.
Many technology companies, including Apple Inc and Google, have made encryption a default setting in their products, a trend spurred in part by the 2013 Edward Snowden revelations about government surveillance.
Burr said he did not expect much cooperation from tech companies on the encryption issue, but he said they may not have a choice if national security is the issue.
"If it means that people are going to have to change their business model, then so be it," Burr said. (Additional reporting by Eric Beech; Editing by Toni Reinhold)