The European Union should consider forcing Internet firms to help security services tap into coded emails and calls as part of a new strategy to combat militant attacks, the EU counter-terrorism coordinator says.
The controversial proposal appears in a briefing paper from Gilles de Kerchove for EU interior ministers meeting next week which was reviewed by Reuters. The confidential document, drawn up after this month's Islamist violence in Paris, puts forward a range of areas in which EU states can improve their cooperation.
De Kerchove noted that scandal over US spying on global networks had prompted companies to offer more encryption. This can thwart official monitoring, even where police have warrants.
Stressing that any measures must respect fundamental rights, he wrote: "The Commission should be invited to explore rules obliging Internet and telecommunications companies operating in the EU to provide ... access of the relevant national authorities to communications (ie share encryption keys)."
A spokesman for de Kerchove declined to comment on the paper.
A proposal by British Prime Minister David Cameron that firms share encryption keys was condemned by civil liberties groups. Some also questioned its technical feasibility.
De Kerchove's suggestion drew criticism from Jan Philipp Albrecht, a Greens member from Germany, who accused him of reaching for "the toolbox of repressive regimes ... by asking for a back-door way into encrypted communication".
In an interview with Reuters this week, de Kerchove insisted: "No one wants to turn Europe into a police state or a Big Brother society."
But, pointing to demonstrations this month in support of victims, he said there was a popular desire across Europe to tackle radical groups and prevent young men traveling to fight for militants in Syria and returning to mount attacks at home.
De Kerchove, a Belgian lawyer who has held his role since 2007, also told Reuters he recommended governments withdraw the passports and travel rights of people suspected of planning to go abroad to fight with Islamic State: "It's like driving a car without a license," he said. "You don't have to demonstrate the intention of the driver or where the car is going."
De Kerchove said he expected governments to adopt an EU approach that would build on improving cooperation under systems already available, such as for Europe's passport-free Schengen travel zone, and on existing institutions such as Europol and Interpol. The need for new legislation was limited, he said.