Law enforcement the world over seeks access to people’s communications to help fight organized crime and terrorism. There is some question in the US on whether and to what extent this is already being done. Following the Boston bombing there is a focus on whether the bomber’s widow was aware of the plans. On Wednesday, CNN’s Erin Burnett interviewed Tim Clemente, a former FBI counterterrorism agent. The question was whether the FBI would be able to discover the content of past telephone conversations. “There's no way they actually can find out what happened, right, unless she tells them?” asked Burnett.
"No, welcome to America. All of that stuff is being captured as we speak whether we know it or like it or not,” replied Clemente. This is total surveillance of the kind envisaged by the Pentagon’s Total Information Awareness program proposed after 9/11.
Meanwhile, on 1 May 2013 a paper was submitted to Cornell University by the Los Alamos National Labs. It describes “a new, scalable instantiation of quantum cryptography providing key management with forward security for lightweight encryption, authentication and digital signatures in optical networks.” Quantum cryptography is the Eldorado of security, promising the potential for perfect communications secrecy. The concept is easy to understand. The laws of quantum mechanics state at the photon level, a particle cannot be measured without altering it. A message encoded in photons could not be read without altering it – which means the recipient will always know if it has been intercepted.
In cryptography, the one time pad (OTP) is often considered to be the only theoretically secure encryption. But it can only be as secure as its key exchange; and that – until now – cannot be guaranteed. Quantum cryptography guarantees the distribution of OTP keys that have not been intercepted, providing the potential for perfect security in digital communications. The Los Alamos paper, Network-Centric Quantum Communications with Application to Critical Infrastructure Protection, claims that a quantum ‘internet’ has been demonstrable for two-and-a-half years.
The big problem in quantum security is that its security strength is its biggest weakness – the ‘interception’ necessary for routing will alter the message. Los Alamos solves this issue by using a hub and spoke network, with the hub containing its own one time pad. Computer A transmits to the hub which receives, re-encodes, and communicates to the destination computer B. This works, but is eminently non-scalable for the wider internet.
Scalability is what Los Alamos is working on. “We’re trying to come up with better scaled architecture for quantum networks,” lead researcher Richard Hughes told Forbes. “And by scaling I mean, in our approach, if you have many clients and one server. However, you don’t have to actually send secure communications through the central server. Secure communications can go by any path you like. There are quantum links between each end client and the server, and the server manages the encryption keys.”
Nevertheless, such a system will only be as secure as the hub, and scalability remains problematic for the wider internet. The MIT Technology Review points out, “Various teams are racing to develop quantum routers that will fix this problem by steering quantum messages without destroying them.” It adds that the Los Alamos approach “will become obsolete as soon as quantum routers become commercially viable. So the question for any investors is whether they can get their money back in the time before then.”
One thing seems clear – total security via quantum key distribution is inevitable. What that will do to law enforcement’s desire for total surveillance remains to be seen.