Cyber security presents a big enough challenge as it is when it's just your Gmail password and online banking. A whole other underground Internet exists where criminals can buy and sell anything from stolen data and exploits to assassinations. With the NSA entangled in a massive privacy-breach scandal and hackers taking control of everything from iPhone cameras to car brakes, ordinary users are caught increasingly helpless in the midst of the digital cross-fire between powerful state, corporate, and criminal organizations.
But the cyber world is about to get exponentially more complicated in the next couple of decades, experts say, as a new computing device called quantum computers and other futuristic advances learn how to process information much faster than the laws of classical physics currently allow.
Experts disagree on whether new devices sold by the Canadian firm D-Wave Systems to Lockheed Martin, NASA, and Google for a reported $10 and $15 million (depending on the version) can fully harness the bizarre potential of the quantum world, but say that such a computer would make obsolete all contemporary encryption and endanger all of the financial and medical information that is currently being transmitted over the Internet, alongside almost everything else stored in a digital format.
Other, far more efficient techniques of safeguarding our security are being developed. But for the time being, paradoxically our best guarantee of privacy is the limitation of the technology available to us. As powerful as modern computers are, they cannot process the vast amounts of data required to break advanced encryption algorithms or to monitor the daily activity of most ordinary citizens.
Even the supercomputers of the NSA are unable to completely process all the information they collect. Documents leaked by its former contractor Edward Snowden show that the agency is forced to delete most of it from its servers within "three to five days."
Quantum computing would change all that. While ordinary computers use miniature transistors that can only store information in the form of 0s and 1s, quantum computers encode quantum bits (or qubits) in exotic subatomic particles that function both as particles and as waves. Qubits, unlike bits, can hold multiple values at the same time and participate in millions of simultaneous calculations.
"If quantum computers with 1,000 or more qubits can be built and operated with minimal environmental influence—and that is a big if—then problems that are too hard for classical computers could be solved," explained Paul Benioff, the Argonne National Laboratory researcher who first came up with the idea of a quantum computer back in 1981, in an email.
"The canonical example is Shor's algorithm for finding the prime factors of a very large number, for example one with 100 to 200 digits. Solving this problem on the fastest classical computer would take many thousands or millions of years. On a quantum computer this problem could be solved in a practical amount of time.
This problem is important because this difficulty of finding prime factors is the base of the secure encryptions used by banks and law enforcement and other agencies. In principle, quantum computers would compromise the security of these encryptions."
Quantum computers would also improve the ability of corporations such as Facebook and Google, which collect billions of clicks every day and process massive amounts of user information, to use the data they mine in order to learn things about us and to predict our behavior. "These kind of quantum machine learning algorithms … are natural problems for a quantum computer, and could be implemented using considerably smaller quantum computers than those required for code breaking," wrote Seth Lloyd, who directs the WM Keck Center for Extreme Quantum Information Theory at the Massachusetts Institute of Technology, in an email.
Though quantum computing will make it easier to break conventional cyber-security measures, it will also offer up powerful new tools for privacy and security. Quantum searches would process massive numbers of entries without accessing individually "more than a tiny number of [them]," said Lloyd, and ways of analyzing data could be developed such that "privacy is guaranteed by the laws of physics."
Quantum communication, moreover, could in the future be relayed through pairs of entangled particles which defy Einstein’s special relativity theory and exchange information instantaneously in such a way that no other particle can take part in the communication. Quantum cryptography, which in theory could guarantee unbreakable privacy, is already available commercially, and is currently being perfected.
"Quantum computing is expected to drastically change the field of cryptography," wrote Kurt Baumgartner, a senior researcher at Kaspersky Lab, a major anti-virus and Internet security firm, in an email. "Quantum computing would be able to break [currently available encryption], but of course, new forms of data protection will rise and are on the rise."
Experts say it is hard to predict when exactly quantum computers will be sufficiently developed to change the rules of cybersecurity, but a "decade or two," according to Lloyd, would be a reasonable prediction. A major hurdle developers face is that any interference—even attempts to read the calculations—could make the system lose its quantum power and revert to ordinary computing methods. But scientists are making progress.