US authorities have long been concerned about the increasing use of encryption – the basis of digital security – by tech companies.
Hannigan's comments followed similar criticisms from the FBI director, James Comey, who has charged that the increasing use of encryption aids criminals and terrorists and is leading us to a "a very, very dark place".
If you want evidence that US intelligence agencies aren't losing surveillance abilities because of the rising use of encryption by tech companies, look no further than the testimony on Tuesday by the director of national intelligence, James Clapper.
Web users' increasing use of encryption is another live issue.
We decided to be far more careful and got training on the use of encryption methods.
Certainly there are ways the US can improve cybersecurity, including encouraging the ubiquitous use of encryption.
And there is ample evidence that terrorists have made use of encryption technologies, which are difficult to break.
Three letter agencies wanted it for the state but feared widespread use of encryption could hamper intelligence collection.
In response, big American cloud firms have stepped up their use of encryption to protect the data they handle.
Last month the director of the FBI, James Comey, called for "a regulatory or legislative fix" for technology companies' expanding use of encryption to protect user privacy.
And the rising use of encryption technology has long been a concern of the F.B.I., which has said the technology could be devastating to criminal investigations.
