Hannigan was in US in March 2016:
7 March 2016: GCHQ: Director Robert Hannigan dispels myths about encryption in MIT speech
In a speech entitled “Front doors and strong locks: encryption, privacy and intelligence-gathering in the digital era” Director GCHQ shares his thoughts about this pivotal topic with an influential audience at the Massachusetts Institute of Technology
https://www.gchq.gov.uk/news-article/director-robert-hannigan-dispels-myths-about-encryption-mit-speech
Bletchley Park: Robert Hannigan CMG
Robert is ... one of the few non-US citizens to be awarded the US Intelligence Distinguished Public Service Medal.
Wikipedia: National Intelligence Distinguished Public Service Medal
The Director of National Intelligence (DNI) established the award on October 1, 2008 to acknowledge individuals who rendered extraordinary service at considerable personal sacrifice and who were motivated by patriotism, good citizenship or a sense of public responsibility.
Recipients:
Mr. Robert Hannigan (2017)
https://en.wikipedia.org/wiki/National_Intelligence_Distinguished_Public_Service_Medal#cite_note-3
the GCHQ link in reports on Robert Hannigan’s MIT speech is broken, but here’s the cached version - no mention of Russia, which only becomes his obsession (reference his Wikipedia page posted earlier) after he quits, Trump is President & the RussiaRussiaRussia meme has begun.
(cached) GCHQ: Director Robert Hannigan dispels myths about encryption in MIT speech
Last Updated: 07 Mar 2016
In a speech entitled “Front doors and strong locks: encryption, privacy and intelligence-gathering in the digital era” Director GCHQ shares his thoughts about this pivotal topic with an influential audience at the Massachusetts Institute of Technology.
News article - 07 Mar 2016
Robert Hannigan spoke at MIT on 7 March about encryption, privacy and intelligence-gathering. In his speech he highlighted GCHQ’s support for the development of strong encryption, explored its moral dimension, and explained GCHQ’s support for the development of a constructive understanding among all who have a stake in the Internet.
To illustrate GCHQ’s role in the development of strong encryption,GCHQ are making available two papers published internally in 1970 by James Ellis on non-secure digital and analogue encryption. The digital paper is a key document in the development of public key cryptography; the analogue paper highlights thinking which was not really taken further at the time, but which is intriguing today.
Robert Hannigan made the point that public key cryptography and its development have completely transformed the way that people can interact securely: it is impossible to imagine today’s Internet without it. He spoke with pride of James Ellis’s contribution, but also paid tribute to work done by other great people inside and outside GCHQ, discussing the sheer boldness of the concept that reversed centuries of assumptions about how communications could be protected. He drew hope from this, and suggested that their achievement gives hope that current difficulties can be overcome, and that government agencies, the technological industry, and the users of the Internet all have a place in this discussion.
https://webcache.googleusercontent.com/search?q=cache:qxMcHBdiBVgJ:https://www.gchq.gov.uk/news-article/director-robert-hannigan-dispels-myths-about-encryption-mit-speech+&cd=10&hl=en&ct=clnk&gl=au
MIT: Internet Policy Research Initiative: Event: Robert Hannigan – GCHQ (UK) 7 March 2016
IPRI hosted Robert Hannigan, the head of the British intelligence agency GCHQ, at MIT in March 2016. He met for most of the day with researchers and then gave a public speech to a group of about 150 people on campus. He spoke at length about encryption and the IPRI Keys Under Doormats report. He said he hopes technology companies and academic researchers will find ways to let government investigators get into encrypted devices without creating broad “back doors” that undermine computer security. He also spoke of how law enforcement and intelligence officials want only targeted ways to stop what he called “abuse of encryption” by ISIS and other terrorists and criminals. “It should be possible for technical experts to sit down together and work out solutions,” he said. “I am not in favor of banning encryption. Nor am I asking for mandatory back doors. … Not everything is a back door, still less a door which can be exploited outside a legal framework.”
LINKS TO SPEECH & FLYER AT BOTTOM ARE BROKEN; IPRI Keys Under Doormats Report LINK IS WORKING.
https://internetpolicy.mit.edu/robert-hannigan-gchq-ipri-march-2016/