Hi, this is Suparna Goswami, Associate Editor with Information Security Media Group. I have the pleasure of speaking with Robert Bennington, Co-founder and CTO at Spectral. We will be talking about quantum communication, what impact it has on cybersecurity, and how it affects the security community. Welcome, Robert, to the ISMG discussion.
Thank you. So, Robert, quantum technology has been spoken about a lot of late, and there are more and more quantum technology companies that are coming up. But what exactly is quantum technology, and where exactly does quantum communication fit in here? Yeah, so quantum technology is basically anything based on quantum physics.
Quantum physics is the physics of the very small things. Quantum physics has been around for a hundred years or so, but the quantum technologies are a lot newer. There was a sort of first wave of quantum technologies back in the 50s and 60s. These are things like lasers and semiconductors, where an understanding of quantum physics helps people manipulate materials.
But the modern sort of hype for the quantum technologies is really the second quantum revolution, and that's more about exploiting some of the quantum weirdness, so things like quantum entanglement and the no-cloning theorem. This second quantum revolution, quantum technologies, really fall into three categories. These will be quantum sensing, quantum computing, and then quantum communications, which is what I'm working. So quantum sensing is really all about using these quantum weirdness to make more accurate measurements than were possible with earlier technologies, things like measuring gravity and measuring time and distances and things.
Quantum computing is the really powerful one for developing a whole new way of doing calculations. It's unlocking and will unlock many scientific discoveries to the kinds of calculations that it will be able to do. And then quantum communications is about using quantum physics to distribute quantum information. So this has applications to quantum computing.
So quantum computers want to talk to each other, or perhaps if they want to talk to some of these quantum sensors or any of these quantum devices want to talk to each other, then to talk in a quantum way, they would have to use quantum communications. This often means individual particles of light. Where quantum communications is interesting and relevant at the moment is in the fields of cryptography and secure communications. So the sort of the first applications of quantum communications are in secure communications.
Sure. So you said that the first application of quantum communication is in secure communication. Our listeners are the security community. So what does this have to do with security and how does it affect our security community?
Yeah, I mean, you already have ways of doing secure communication systems. Why do we need this? Well, one of the reasons really is that quantum computing is threatening the status quo, many of the current secure communication methods. So quantum computers, one of the things that they will be very good at is factorizing large prime numbers.
And one of the assumptions of modern RSA cryptography is that factorizing large prime numbers is very difficult for conventional computers to do. Modern RSA cryptography would be broken as soon as machines are able to factorize large prime numbers. So this threat that once quantum computers become powerful enough that they will be able to break so many secret communication systems, this threat is really motivating people to look at new ways of doing cryptography, ways that will be secure against computational attacks of any kind and really thinking from the ground up how we do secure communications. So, Robert, spectral, you know, is a space company, though, right?
So how does the entire thing work? If you kindly walk us through the process, it will be fascinating for our listeners, I'm sure. Sure. Well, so spectral, where I work, is involved in space-based quantum communications.
And the first application of this is in space quantum key distribution. And this is a method for delivering incredibly secure symmetric encryption keys to anywhere in the globe. So symmetric encryption is secure against attacks from quantum computers because there's not patterns there for it to try and crack in the same way that there is with a public-private key system. The problem with symmetric communications is that you need to securely deliver encryption keys, so symmetric encryption keys, to the two users or the two nodes that wish to communicate.
So quantum key distribution is a method using quantum communications to deliver these secure encryption keys in a way that is tamper-proof. So you can tell if there's someone trying to intercept the transmission and make a copy of these encryption keys. And it's also fundamentally random. So that means that the encryption keys delivered through QKD, there's no patterns there which can be cracked by any computer.
There's no prime numbers factorized or any sort of mathematical problem there to do to attack. And so this makes them fundamentally more secure than any kind of public key encryption system. Now, you ask why we're doing this from space, because most encryption systems don't use satellites at the moment. And that's because to deliver these encryption keys requires very weak light signals.
And to send these light signals, you have to have a direct line of sight or you have to have a fiber optic connection. The fiber optic connection is very lossy, so it only works over a few hundred kilometers or so. So if you want to speak to someone in a city more than a few hundred kilometers away, then you start to have to use other nodes. And the most practical way to communicate over long distances to the other side of the planet or to the other end of the continent is by using satellites to deliver encryption keys to these two sites.
So the satellite becomes a trusted key delivering node that travels all around the world delivering keys to the nodes which communicate. So these keys are then used to encrypt the messages and messages are then sent over the internet or however people are communicating conventionally. So Robert, essentially, you're using satellites essentially. So what are the security concerns when you use a satellite?
And then what does that the security community needs to be concerned about? Sure. Can we receive these keys from the satellite? You need to have an optical ground station.
So an optical ground station is like a big telescope, something you use to look at the stars. It's something like that. And this telescope will have to track the satellite and receive the quantum communications as the satellite flies over. So this is quite a different way of receiving keys than companies might be used to.
Now, the beauty of QKD, quantum key distribution, is that you can, by running statistical tests on the keys that you receive, you are able to prove that no one outside of your building can have any knowledge of the key material. So you just need to make sure that your telescope is secured and that no one has any back doors into your telescope. You need to trust that the satellite system you're working with has no back doors at that side. But any eavesdropper that's between the satellite and the telescope trying to intercept the key, they will be revealed during these by these statistical tests that are made on the key and that's part of the process.
So, yes, the keys will be delivered then from the optical ground station into your system. So this might be into the HSM box that's encrypting traffic exiting from your site or your building to the outside world. And what this would replace in a conventional context is the smart cards that might currently be used to set up symmetric keys between sites like this. So in the current scenario, you might have a secure courier who delivers smart cards containing symmetric keys and these are plugged into boxes at your various different sites.
Instead of that system, you can now have quantum sites flying over delivering these keys to the telescope. And this removes the requirement for a trusted courier. It makes the process a lot more automated and it means you can refresh these seed keys at a much more, much faster rate than you can with conventional courier systems. So this is intrinsically a lot more secure than the current situation.
Great. Fascinating. Thanks a lot, Robert, for sharing your thoughts on quantum communication. Thank you.
You're listening to Robert Bennington for ISMG Asia. This is Suparna Goswami. Thank you for listening.