Researchers at QuTech have made a breakthrough in quantum internet security. Their development of a link layer protocol utilizes entanglement to bring the idea of a quantum network from science fiction into a tangible modern reality. Such a development is paramount in the world of cybersecurity, and could help to prevent future attacks from advanced quantum computers.
The concept of quantum computing has been around for decades.These extraordinary machines exploit the quantum phenomena of superposition and entanglement to produce remarkable processing capabilities. The first fledgling machines, such as the IBM Q System One, cannot yet outperform classical computers at useful tasks; but they do raise concerns for cyber-security.
Introducing: The quantum internet. It the lesser-known cousin to quantum computing, but we are far closer to it than most people realize. It is highly likely that the quantum internet won’t look or feel any different – in fact you may not even notice it arrive - but it utilizes those same quantum principles to allow perfectly encrypted communication that, in theory, simply cannot not be cracked; a welcome sigh of relief in a rapidly-expanding digital world.
If a powerful enough quantum computer were to be developed, today’s encryption methods would not be able to withstand a quantum attack. Current cryptosystems for secure data transmission, such as the widely-used RSA (Rivest-Shamir-Adleman), rely on generating security keys which are easy to verify but very hard to crack. An example of this is factoring large numbers into prime numbers. Using traditional computers, it takes significantly longer – longer than polynomial time - to factor very large numbers into their primes, than it does to check that answer by simply multiplying the factors together. A quantum computer would not face these same challenges, and could theoretically crack the encryption in seconds.
In 2017, NIST (The National Institute of Standards and Technology) started receiving submissions for “post-quantum cryptography” strategies that could help to protect against any future quantum attacks. Essentially, they are looking for a classical algorithm that a quantum computer cannot crack. Such an algorithm would be almost unnoticeable to the untrained eye – perhaps secure web pages will be listed “httpq” over “https” – but could be one of the most important changes in data protection history.
In addition, researchers from QuTech, Delft University of Technology, have just published a paper detailing the world’s quantum first link layer protocol. In classical computing, a link layer protocol enables networks to overcome problems caused by imperfect hardware. One such example is Wi-Fi, which utilizes these protocols to overcome interruptions and interference in radio signals to transmit data reliably.
For a quantum network to be developed, the same level of reliability in data transmission is required.
In our work, we have proposed a quantum network stack, and have constructed the world's first link-layer protocol for a quantum network. Our link layer protocol allows us to reliably generate entanglement between two network nodes connected by a direct physical link, such as a telecom fiber.
Professor Stephanie Wehner, QuTech
Entanglement is the phenomenon which provides a potential quantum network with absolute security. When two particles are entangled, they are in a state where nothing else can share even a small portion of their connection. Essentially, it is physically impossible for an observer to eavesdrop on this entangled network, eliminating many of the issues that current classical cryptography faces.
The team still faces challenges - quantum entanglement brings a very different meaning to the concept of “connection” than in classical systems - but this is a huge first step. They will now focus on producing an entanglement between network nodes that are not connected by a fiber, utilizing an intermediary node instead.
Although a quantum cyberattack is not imminent; developments such as these are of huge importance for future internet health, and should help to quash security fears when the age of the quantum computer does indeed arrive.