Information Commissioner Christopher Graham has warned the government not to make knee-jerk decisions over data privacy following the Paris terrorist attacks.
Speaking at an event in Liverpool this week, Graham said: "I do not underestimate the real challenges posed by international terrorism - particularly after last week's shootings in Paris. But thinking about Paris - and the Woolwich murder here too - we need cool heads to analyse carefully what information the security services had access to and how they used it, before necessarily concluding that we must give them access to more and more of our private information."
He added: "We must avoid knee-jerk reactions. In particular, I am concerned about any compromising of effective encryption for consumers of online services. Every week, we hear about cybercrime and online services being hacked. And we read about the threat of cyber warfare."
Graham said citizens, businesses and nation states needed to protect themselves. He said internet companies are "understandably offering their customers online services that are better encrypted following recent security incidents."
Last week, the head of MI5 Andrew Parker made a speech in which he said: "We all value our privacy and none of us want it intruded upon improperly or unnecessarily. But I don't want a situation where that privacy is so absolute and sacrosanct that terrorists and others who mean us harm can confidently operate from behind those walls without fear of detection."
Graham responded in his speech: "Hear, hear. But neither do I want a situation where the security imperative closes down every debate about rights and obligations."
In matters of security, said Graham, the UK now needed an "effective American-style" Privacy and Civil Liberties Oversight Board or an equivalent to "find the right balance".
He added that a year ago he made a submission to the parliamentary Intelligence and Security Committee on the subject of consumer encryption and oversight arrangements, and that "we are still waiting for the Committee to report".
Graham said it was "encouraging" that the government is currently consulting on setting up a Privacy and Civil Liberties Board. "We will though need to be sure that what is proposed really would provide effective and balanced oversight," he added.