As the legal tussle between Apple and the FBI continues, the head of UK intelligence agency Government Communications Headquarters (GCHQ) has called for more collaboration between academics, civil society, government, and the tech industry to find a solution to the ongoing encryption debate.

In a speech delivered at Massachusetts Institute of Technology (MIT) on Tuesday, GCHQ director Robert Hannigan said, "We should be bridging the divide, sharing ideas, and building a constructive dialogue in a less highly-charged atmosphere. That's why I'm here."

Although Hannigan did not point to any specific cases, that "highly-charged atmosphere" is likely referring to the current heated debate over law enforcement access to encrypted data. This has recently become an increasingly controversial issue, with the FBI attempting to legally compel Apple to weaken the security of one of its devices to assist in an investigation.

Hannigan brought up the threat posed by the so-called Islamic State (ISIS) and said he hoped that tech companies would work with government to combat the terrorist group.

More generally, he suggested that increased collaboration between government and companies "will help bring us closer to the goal which I think is shared by all sides: moving those who misuse encryption and abuse the internet and web into the reach of the criminal justice system. Even agreeing this goal frees us to begin a new approach."

Hannigan explicitly referred to the anonymity network Tor, which he called "a brilliant invention that is still invaluable to those who need high degrees of anonymity, notably dissidents, human right advocates and journalists; but an invention that is these days dominated in volume by criminality of one sort or another."

It wasn't immediately clear if Hannigan was referring to the so-called "dark web," the relatively small collection of websites hosted on the Tor network, or the Tor network more generally, which is mostly used to browse the normal web. He added that, "The technology of the internet and the web is morally neutral, but those of us who use it aren't."