Superposition Guy Podcast — Niccolo Somaschi, CEO, Quandela

Niccolo Somaschi, CEO of Quandela, is interviewed by Yuval Boger. Niccolo describes the company’s approach to quantum computing, emphasizing the use of photonics and semiconductor technologies to manipulate photonic qubits. He highlights Quandela’s focus on building commercially useful quantum computers, the development of a unique programming framework for transforming gate-based circuits into photonic operations, the deployment of their 6-qubit processor, the challenges for scaling photonic quantum computers, and much more.

Listen on Spotify — The Superposition Guy’s Podcast

Transcript

Yuval: Hello, Suvi. Hello, Miikka. Thank you very much for joining me today.

Suvi Lampila: Thank you for inviting us.

Miikka: Yeah, thanks for having us.

Yuval: Wonderful. So, Miikka, who are you and what do you do?

Miikka: So, I’m Miikka Sainio, I’m the CTO of SSH Communications Security.

Miikka: We are a European cyber defense company and we are based in Helsinki, Finland. We do have customers all over the world and offices in New York and Singapore. Our founder, Tatu Ylönen, invented the SSH protocol in 1995, actually, almost 30 years ago and then built the company around it. And now, nowadays, as people may know, SSH protocol is one of the fundamental building blocks of the modern internet. So, we build secure communication, access management, and key management products for human-to-human, human-to-machine, and machine-to-machine communications. And with me, I have Suvi Lampila.

Suvi: Hi. Yeah, so my name is Suvi Lampila. I’m a fellow at SSH and I’ve been with the company for over 20 years. And for the past few years, I’ve been working on post-quantum cryptography-related things within our products to make sure that our solutions are quantum safe for the future.

Yuval: A company that’s 30 years old is a little bit unusual on this podcast. And obviously, 30 years ago you were not involved in quantum. When did the need for quantum safe security come up and when did you start working on it?

Suvi: It was kind of a research project at first, and I can’t remember exactly when, but I do remember in 2019 when things started to heat up so that there was more pressure from our customer base to start working on the solution. So it was kind of something to tinker on, but then we kind of started to take it seriously at that point and already in 2021, we had our NQX, which is an IPsec based network encryptor solution available on the market in the Northern Europe. And then a few years ago, our Tectia solution that is a secure shell based solution had its first of PQC algorithms and then our other product lines followed suit the same year. So we’re kind of in front of trying to put this into actual production in our customer base.

Miikka: Yeah, also, back in the day, we were one of the founding members of PQC Finland, which was kind of a cooperation between companies for post-quantum cryptography. 

Suvi: And now we’re part of the consortium that is led by the National Institute of Standards and Technology in PQC migration. So there’s a bit over 20 organizations globally trying to figure out how we’re going to do this migration to PQC in practice. So that’s where we are right now. 

Yuval: What is the state of education of the market? I’m guessing that ten years ago, customers were not really aware of the store now decrypt later concern. But when you speak with customers today, are they generally worried about that? Or is there still a lot of market education that needs to be had?

Suvi: I think you’ve hit the nail on the head there that it’s a major thing to educate this stuff because there’s quite a lot of misunderstandings of like, how do we transition and what needs to be done at what stage. So, the retroactive attacks on the key agreement algorithms of the current Diffie-Hellman and Elliptic-curve Diffie-Hellman that has to be protected first. So we need the Crystals-kyber key encapsulation mechanism in place already now. And we did ourselves a bit of a disservice by naming this post-quantum cryptography that implies that something happens after the quantum era when there are things that need to happen well before the cryptographically relevant quantum computer comes along. So there’s the education side of it that needs to be tackled. And oddly enough, this sort of recording attack did kind of enter the minds of some of our customers already long time ago because we have things in place within the protocols that are not so much quantum-safe, but they’re kind of quantum resilient. So for instance, we do re-keys frequently so that every gigabyte or every hour in Tectia we do the exchange of the session keys again. And that sort of thing is there and it helps in somewhat with the recording attack. But at the end of the day, we need to replace all those old algorithms with quantum-safe alternatives, and getting that thing going is a thing that should be happening already now. We cannot really wait for the final standards and everything to be in place to get a move on. So it has to be an incremental process, and communicating that is also a bit of an uphill battle. 

Miikka: People need to prepare.

Yuval: Let’s assume I’m a multinational bank, and I contacted you a couple of years ago. I was aware of the concern I wanted to upgrade the security of my network. How does the process look like, and how long would it take until I’m relatively comfortable that I’m protected against future quantum attacks?

Miikka: But it depends completely. Yeah, we like more recently we have had the chance to work with a lot of companies in operational technology or OT and in OT the software stacks or the devices themselves have really long lifetimes and they don’t update the devices that often because of various reasons.

But also because perhaps the updates aren’t even available so in those cases.

To be quantum safe the only way or perhaps to be safe in general.

The only way is to encapsulate or tunnel those connections using quantum safe algorithms. So we really have to be quite pragmatic with our customers how to make them safe. It’s nice to see that Google and Cloudflare and other large internet players are also jumping into the bandwagon and implementing TLS stacks which are quantum safe But of course that only helps with certain use cases.

Yuval: Speaking of time, some data is more time-sensitive or has a longer shelf life than others. An attacker might not care what I ordered in a restaurant a week ago but may be interested in my life insurance policy or my health records. When you go to customers, what do you tell them about the timeline of when do you expect that quantum computers will be sufficiently strong to break encryption?

In the time frame, what shelf life for data should they be worried about?

Miikka: I couldn’t imagine four or five years ago that the large language models are used in kind of such a context and such a way that they are used today and what they are capable of. So, when things happen, they happen really quickly. So I suspect that the same will also apply to quantum computers once it happens.

Suvi: And I think also one misconception is that we’re waiting for the perfect implementation of the quantum computer when the threat to current encryption is going to be in my mind, the combination of the classical computing power with the supercomputers and the quantum computers coming together to wreak havoc. So, like there could be error correction done on the quantum computing side, but then as well like optimization done on the classical computing side that might change things in a way. And then who knows there might be somebody who comes up with the equally great brilliant idea like Peter Shor did back in the day that kind of started the whole feasibility of breaking the asymmetric encryption with the quantum computer and it could be a kid who has been playing around with Qiskit these few years that comes up with something that speeds up things or just narrows down the search in a way that it becomes more feasible. So we’re kind of raising both against the quantum computers and advances that can be made with the classical supercomputers and the combination. Like in Finland we have now the third fastest supercomputer in the world situated in Finland and that has been connected with the baby quantum computer from IQM that the researchers can use for free, apply for time to use the combination. So this field is kind of moving fast where there’s so much money put on the quantum computing side right now that I wish that some of it would also be put on this defending side of things in an equal measure. Right now the uniqueness is that it has been around and available for production already for a few years. So that’s one aspect of it, but we’re able to do it. We’re able to put it into battle-tested solutions that have stood the test of time up until now and we have kind of like a holistic view in many ways when it comes to this, but I don’t really see that we can tackle all even though we are like well-established company. Any company that comes to you and says that they are able to solve this completely is really not telling the truth. This will require a lot of industry wide effort to get, for instance, the authentication keys sorted out and all that. So I see it as a like a big push from the whole industry to get to the quantum-safe world.

Miikka: Having said that, we really do have a really strong stack in supporting customers from moving from weak algorithms to quantum-safe algorithms through SSH key management and then SSH client-server solutions and our access management solutions which are all quantum-safe. So we have kind of quite a complete solution for customers starting from the discovery and ending to actual securing connections between different entities in the organization. And yeah.

Suvi: In a way, it’s not our first rodeo also. We’ve been through these sort of similar things before with that SHA-1 to SHA-2 migration and so forth. So hopefully that is something that will help us also this time around that we were able to do timely things in a manner where it makes sense. And then I think like many of our largest customers benefit from the lessons learned that we get from the other customers. So there’s also that the established customer base helps one another. 

Yuval: When you look around the world, do you see some countries that are taking this more seriously than others? [silence]

Suvi: Well, I think many countries at least the ones that I’ve visited and had some conversations and we look at the NIST efforts of the standardization being very much like international effort. And there’s many places have taken the stance that they’ll wait and see what the US does, what NIST recommends and then take it from there. That’s, for instance, how UK has positioned itself, that they will follow NIST recommendations and so forth. Finland hasn’t really had a specific policy on this, but during that PQC Finland process, we did have a policy brief on it, and our recommendations are pretty much in line with what the NIST is saying apart from that, we do recommend the hybrid approach, which combines the classical key exchange algorithms with the PQC algorithms for a time being. But then there are others like the German BSI and the French ANSSI that recommend likely different algorithms compared to the NIST. So there is a legislation push going in different parts of the world. But I would say that most likely these things, we don’t necessarily get to see what is done on the national level. We do get to see the glimpse into the commercial space of things. So most are waiting for the NIST to finalize the standardization project and following that. We do recognize that we need certain interoperability as well. So there is that good reasoning for it. 

Having said that, it doesn’t mean that you can just lay low and wait for somebody else to figure these things out for you. So there needs to be certain things that organizations need to look at already at this stage because the well, the retroactive threat for one. So we cannot just wait until everything is ready to get moving on with that. What keeps me up at night?

Yuval: From a business perspective, what are you worried about? What keeps you up at night? 

Suvi: Well, there has been so many times now, even this past year, when there has been news about RSA 2048 being broken. And well, so far, that hasn’t been the case, but I’m kind of hoping that we get to that position that when that call comes in, I’m going to be able to confidently say that, you know, we have moved on to post-quantum cryptography long ago. It doesn’t concern us because of that. It’s not used anymore. So my kind of concern is that something will cause an avalanche of things that it will happen in an uncontrolled way. And I’m caught between a rock and a hard place with our customers in that sense. But at least we’re working hard on trying to avoid that scenario. So having said that, I have one thing that I kind of think, in my own mind, is that the chances are that we won’t learn about the cryptographically relevant quantum computer. It’s going to be a bit like Enigma back in the day that whoever comes up with that, they’re not going to reveal it to the world. They’re going to let their own ship sink before they reveal. So maybe there’s a museum like there’s now in Bletchley Park in UK 50 years from now. And then we learn when these things actually were already operational. But yeah, that’s the thing. It probably might be that that museum isn’t open before my time is up on this planet. But hopefully we’ve taken that into consideration already before then.

Yuval: And as we get to the end of our conversation today, I wanted to ask you a hypothetical and perhaps Mika, you could go first and then Suvi. If you could have dinner with one of the quantum or security greats, dead or alive, who would that person be?

Miikka: This is kind of a difficult one, but I think that for quantum mechanics it would be David Deutsch. Because it would be interesting to talk about the many worlds in the interpretation. And I don’t know enough to have a view or belief in one direction or another, but it would be nice to learn or hear about his views. 

Suvi: Yeah, for me, I’m kind of leaning toward a dinner party that I would really much like to invite Peter Shor to that, ask him to bring somebody he thinks would be great to have. And then this brilliant cryptographer, Maria Eichlseder, who I had a pleasure to meet last year at one of these events in Forum Alpach, where we were speaking that I would love her to be involved as well, because I have quite a bit of understanding right now of the post quantum cryptography when it comes to the asymmetric side of things. But she’s working already on the symmetric, the future, the lightweight encryption algorithms that would replace the eventually symmetric stuff. So it would be lovely to get to see her again and ask her to bring other people into the party to discuss.

Yuval Boger: Hello, Nicolo, and thank you for joining me today.

Niccolo Somaschi: Hello, Yuval.

Yuval: So who are you and what do you do?

Niccolo: I’m the CEO of Quandela, a quantum computing company based in Europe, with head-quarters in Paris, which I co-founded in 2017, together with Valerian Giesz and Pascale Senellart. Pascale Senellart who is a senior scientist at the National Research Centre CNRS, member of the Academy of Science and of the presidential council for science.

Quandela builds quantum computers with increasing complexity, following the quest of building useful, commercially useful quantum computers which implement error correction.

Yuval: And what is the underlying technology?

Niccolo: Quandela exploits photonics and semiconductors technologies. We manipulate photonic qubits, which are generated through semiconductor nanostructures, semiconductor devices, which also serve as qubits themselves. So it’s a photonic quantum computer that exploits few spin-based qubits, which is a bit of an exotic approach.

Yuval: How does one program a photonic quantum computer?

Niccolo: Well, photons serve as a very efficient qubit because they allow different kinds of encoding. They can be encoded in “dual-rail” using integrated photonic circuits. That’s the main approach. But it also permits to use “time”, “time bin encoding”, both for logic operation and for qubit synchronization. The combination of optical fibers with photonic integrated circuits permits the development of quantum computing systems which are modular and interconnected. So it allows to expand and distribute the computation overcoming some of the issues, qubit size and space basically, which affects several platform manipulating matter-based qubits.

Yuval: So that probably means I can’t just take a QASM program and send it to your computer, right? I have to do something else. If that’s true, what kind of applications or what kind of programs can I run on the computer?

Niccolo: It’s also true what you’re saying, indeed. Photons also support an encoding which is purely photonic, similarly to boson sampling, Gaussian boson sampling, or “standard” boson sampling for discrete variables. Quandela works also with this approach. So this is true. We can use photon as photons and work in a subspace of the Hilbert space, the Fock space, where number of parameters scale faster than hilbert space, for the same number of qubits. So this is a peculiar, interesting approach;, but at the same time we can also treat photos as qubits and convert any gate-based circuits into a pure photonic implementation. And that’s something that also Quandela provides in the full stack approach through its programming framework internally developed, which is called Perceval, that uses a graphical language method in order to optimally transform any CNOT or sequence of logic gates as we would implement in Qiskit, for example, into a sequence of linear optical operations to be implement on the hardware, through compilation and transpilation.

Yuval: And if I compare your computer today to one in two years, for instance, is the number of qubits the measure that you’re looking at, or is it something else? How do I compare photonic quantum computers?

Niccolo: Well, good point. If we look from the user perspective, what will change is surely the computing power and the spectrum of possible algorithms we can implement, both because it will depend, of course, on the number of qubits, but also on the encoding. If we look bottom-up at the infrastructure, that will change a lot. In fact, internally, we are moving to the second generation of machines compared to what we have today. We are moving from manipulation of single photons, as today, as the processor available on the cloud, to the direct manipulation of entangled photons. So, the computing power will scale because the qubit processing and manipulation will be directly entangled photons – graphs – without the need to pre-entangle them before manipulation. And that will allow to increase dramatically the efficiency, reducing the number of resources needed in terms of hardware.

Yuval: You mentioned that transpiler from gate-based applications to the photonic way of thinking, but if I want to focus and get the maximum out of the computer, do I program in gate-based mode, or should I think about the program in a different way?

Niccolo: Today, with some industrial partners we work on trying to bring out the power of the photonic platform directly conceiving photonic algorithms. Certain gate-based algorithms can hardly be transferred into the photonic language, some other more efficiently, especially machine learning based ones, and VQ, variational quantum type because we can manipulate general phases on the circuits. And that’s where we are looking at. Instead of trying to find algorithms for today’s quantum computing platform or simulator, transferring a gate-based circuit into photonics, we take the orthogonal approach and look into classical algorithms which maps directly into photonic quantum algorithms. This goes through mathematical problems based on permanents.

Yuval: You have some computers already deployed, right?

Niccolo: Yes, indeed. Since a year ago, we have Ascella, which is a processor of 6 qubits, available on the cloud, a proprietary cloud. at the same time we are working for upgrading the platform on the cloud, and to provide on-premise machines to data centers. That’s what we have been doing the past year, providing a machine to OVH cloud datacentre, which is a cloud provider based in Europe.

Yuval: What is involved in on-prem deployment? Do you need a dilution refrigerator? Do you need a lot of space or power supply? How does a deployment of an optical quantum computer look?

Niccolo: Today the on-premise quantum computing machines we provide to customers, are rack-based, the standard server tower rack, which makes them seamless integratable in data center – as they take the shape of standard CPUs or GPUs. They should not be seen as such because, indeed, we use cryogenics, cryogenics for the qubit generators and detectors that work at 3 Kelvin, which is a much, much higher temperature than superconducting qubits. This means that in terms of cryogenic technology, we can use rack size cryostats and rack size air-cooled compressors. This entire machine with compressor itself – consumes a the total power below 3 kilowatts plugged into the standard sockets. These are the current machines. While we will scale the number of qubits, we will multiply the number of these racks.

Yuval: When you think about a 6-qubit machine, obviously there’s learning that you can do with it; therefore, larger qubit machines have larger qubit counts. Is there something truly useful one could do with a 6-qubit machine? And I’m sure the same question could be asked about 16 or 26 qubits. But what are people doing with it?

Niccolo: Today we try to, of course, have utility in the sense of scientific discovery, approximation of some algorithms, and run toy models, of course. However, one focus we had since the beginning was also related to cryptography. And that’s what the first customer purchased the first machine for. the application that we run on this computer is to generate quantum-certified random numbers. Something similar to what Quantinuum and IBM have developed with their platform. What we have done is develop the framework, the theoretical framework in order to use contextuality, to perform Bell inequality measurements on-chip, and still validate this theorem and therefore extract quantum-certified random numbers. This is a simple application, but powerful itself. And we can even call it a quantum advantage in the sense it’s not a quantum computing advantage, but it’s a quantum advantage in cryptography where quantum helps to increase the level of security compared to other classical methods.

Yuval: You mentioned IBM and Quantinuum, and I think certainly IBM, when they think about a larger number of qubits, they say at some point we’re going to need to use interconnects. IonQ, I think the same thing. They have optical interconnects. Now, given that your system is optical from the get-go, how does it scale? Do you need multiple machines and somehow interconnect them, or do you just add more fibers?

Niccolo: A bit of both. As I was saying in the beginning, today we use semiconductors a matter-based qubits, to generate light, to generate the qubits. So the photon itself, the qubits, part of the computation, gets out of the parts of the machine and runs into fibers. So, for us, qubits are already shared over different modules, which helps in the conception of the larger number of qubits machines because, for us, upgrading the number of qubits is adding the number of modules. 

Of course, there is a lot of attention to be put into the stabilization of the qubits through fiber and optimization of the optical links. But yes, this is indeed the approach, and we see it as a good way to start because we bypass some issues that, of course, are related to manufacturing a large size processor itself.

Yuval: I believe you said you started the company in 2017, and maybe you were in quantum a little bit before that. So you’re definitely an expert. What have you learned? What’s new in the last six or 12 months that you didn’t know prior to that?

Niccolo: clearly many things, related to the business and technology, that we should expect surprises coming along. Not scientific surprises because we know where we are going, surprising the sense of players or approaches that could disrupt both the market and the technology along the way. This could be by merging technologies, by changing materials, and therefore allowing the use of more algorithms. From here the idea that we do need to build quantum computers because if we put them out there, “someone will use them”. So instead of just waiting to have the error corrected 1 million, 2 million, 5 million qubits quantum computers, we want to build the ones in between because someone will innovate through them. From what we see, some surprises could come up from the user that will start to test these intermediate machines.

Yuval: You mentioned 1 million qubits, and that conjures some other optical company. Are all optical computers the same in terms of approach, or is there something substantially different between one optical manufacturer and another?

Niccolo: There are many differences. That’s also why photonics has been for a while put aside. because it’s complex to understand and conceptually different and in many flavors. Just as an example, photonic quantum computers can use discrete variables or can use continuous variables. This is the main difference. If we scratch the surface, then we look directly into discrete variables, and there we can find different kinds of architecture. Some are inspired by measurement-based quantum computing, which is different than gate based ones. Some use different materials, and different technologies in order to generate qubits. As we do, for example, we use semiconductor nanostructure- quantum dots, while most of the other players use non-linear processes that, of course, are built into silicon, silicon nitride, or other waveguides. There is an internal kind of creativity, let’s say, in the photonic quantum computing community. And probably surprising will come also from emerging or different technologies and approaches.

Yuval: When you install a system, I think you mentioned OVH, just one of your first customers. Is the computer standalone, or is it used often together with classical compute resources?

Niccolo: So this one is standalone. But Perceval, the programming framework, has everything needed as APIs to be connected to the internal cloud, for example, OVH, which is not opening this machine to their customer because it’s used for internal research purposes. This means that we could directly connect Perceval to other machines, the GPUs or the Atos simulator, and can be optimized to run parts of the algorithms on those. This is something we already do with the simulator, so the quantum simulator shares part of the algorithm with the classical GPU. We see this as very important for the machine to come especially from the user perspective.

Yuval: What is the limiting factor in scaling the machine? Is it laser power? Is it miniaturization? What would it take to take this machine and make it much, much, much larger?

Niccolo: The main engineering problem is losses. Is the transparency of the elements, is the capability to generate one qubit and make it pass through the entire chain of systems and modules and be detected. So what we call the entire losses threshold, has to be very high in order for a certain number of qubits to reach the threshold for error correction. That’s the hardest engineering problem all the companies, to face. Knowing that photonic qubits don’t undergo decoherence itself, the error is not into the decoherence or face flip or bit flip, etc. But losses. One photon is either there or not. And losing a photon is very easy. So in Quandela, what we say is that “every photon counts”.

Yuval: As we get close to the end of our conversation, I’m curious, professionally speaking, what keeps you up at night?

Niccolo: Many things. There are many nights a week, so I share my thoughts. It goes by period and I would say engineering is, of course, the main one, how to allow the teams to get always the best providers, the best technologies, and to let the team do their research without caring about anything else. For example, recently, we’ve been launching our own internal clear room to start developing the fabrication process of most of the devices internally. This, of course, has a lot of infrastructure, a lot of problems related to making these fast and transfer fabrications chain of production from one of the facilities to another. This, of course, needs a lot of attention. And this is an example of the thing we were very careful in doing properly.

Yuval: One thing I wanted to go back to, I think I understand the use in random number generation, but you mentioned machine learning. What makes photonic computers particularly useful for machine learning applications?

Niccolo: As I mentioned before, the fact that machine learning allows the manipulation of a large set of parameters but not controlling each of the parameters. So the photonic approach allows the manipulation of sets of qubits, manipulating the general phase, for example, without going into the control of each one. And there are also many similarities in the computer science term in this approach, from neural network to the large interferometer, which is the main manipulating object in the photonic circuits. That’s why we’re trying to find a smart way to map this kind of mathematical problem to permutation and find a related one, similar one in standard computer science in some small or large set of problems that can still impact industries.

Yuval: And last hypothetical, if you could have dinner with one of the quantum greats, dead or alive, who would that person be?

Niccolo: Oh, wow. Let’s say Heisenberg.

Yuval: And why?

Niccolo: Because there are many questions that I would ask on the general fundamental sense, which I couldn’t find in many of his books.

Yuval: Very good. Nicolo, thank you so much for joining me today.

Niccolo: Thank you, Yuval.