Over the past few days, the term 'kill switch' has been bandied about widely to describe the recent move by Egyptian authorities to shut down Internet services in the country. A lot of people have also been using the term in connection with a proposed bill that would give the U.S. president the authority to disconnect Internet services during a national emergency.
As dramatic as the term sounds, the fact is there is no Internet 'kill switch'. Not physically anyway and not in the way many people likely assume it works. At least for the moment, there is no, one sinister switch or little red button some place that can be thrown to immediately plunge an entire nation into Internet darkness.
What happened in Egypt was most likely far more mundane, according to security experts who know about these sorts of things. It appears as if somebody made a series of well coordinated calls to key Egyptian ISPs and ordered them to make a few changes in some of their routers or maybe even to just pull the plug on them. The shutdown orders were the 'kill-switch'.
"Except in the very tiniest countries, there is no switch, button, or other shutdown interface that would allow a government to turn off all of the Internet service within their borders," said James Cowie, CTO at Internet monitoring firm Renesys.
Instead, such shutdowns are more about communicating a legal order to all providers in a region and to have them obey that order in a timely fashion, said Cowie who has a terrific analysis of what happened in Egypt on the Renesys blog.
"Metaphorically, however, [kill-switch] is an accurate shorthand description of the policy and procedure for implementing such a shutdown," Cowie said.
In countries such as the US or Canada, "the government would find it impossible under current law to convince enough key providers to help them activate the 'kill switch', Cowie said.
But what if a government really wanted to build some kind of a central kill switch? Technically would that be possible?
Yes, according to Craig Labovitz, chief scientist at Arbor Network, a network security firm. "Specifically, one could imagine a special type of control or routing message--and accompanying regulatory mandate--to software / hardware on core routers," said Labovitz who has some interesting graphs showing recent Internet traffic in Egypt on his blog. "Certainly the emergency broadcast system in the US seems to work well."
"But overall the issue is less about technology and more about regulatory powers and enforcement -- especially in countries with strong democratic traditions," Labovitz said.
And even then, "a centralized kill switch would likely require the continuing cooperation of hundreds or thousands of providers to not circumvent the "kill" directive," he said.