Global tech giants and scientists are in a race to build quantum computers, hoping to usher in the Quantum era of computing– faster and more efficient than ever before.

In Bengaluru, a new startup is solving a big problem that might crop up if the world sets foot into the quantum era: that of data security.

Traditional cryptography techniques that rely on complex mathematical problems to keep your data secure tend to fail in the quantum era as quantum computers can solve these easily.

This is where Bengaluru based QuNu Labs wants to make a difference. The startup is currently working on Quantum Key Distribution (QKD), a technology with which encryption keys can be exchanged securely over networks.

“Classical optical networks are unsafe for various reasons and are going to become substantially more unsafe with the advent of quantum computing,” says Mark Mathias, the CEO and co-founder of QuNu Labs.

Traditional networks are unsafe even if it’s encrypted because quantum computers can quickly break cryptography that exists today.

QuNu Labs’s solution uses two channels– one to transmit encrypted data and the second one to transmit the secure private key that’s used to decrypt the data. The data is shared over a traditional network while the secure keys are shared through a quantum channel using photons (light particles).

This way, even if the data line is tapped, the attacker won’t be able to decrypt the data without the encryption key. The key is nearly impossible to tap because intercepting light particles on the quantum channel will change its properties and make it useless for the attacker. The system can also detect such interference and alert users.

Scientists have been dreaming of building quantum computers for over three decades now. And there’s more ground to cover. But the quantum era might be here sooner than we think and cryptography will play an important role in making it useful for a variety of industries.

QuNu Labs, founded in September 2016, is one of the early movers in the space. Anil Prabhakar, who heads the laser optics group at IIT-Madras and Mathias, who has over 35 years experience in electronic product design are the two co-founders of the company.

“It’s much more a reality today than it was a few years ago and it’s very possible in our lifetime,” says Anil Kumar, who used to be the principal investigator at IISc’s Centre for Quantum Information and Quantum Computation. “Cryptography is in fact one of the first areas people want to use quantum technology,” says Kumar.

What is quantum Key Distribution?

Traditionally encryption systems rely on symmetric (private) or asymmetric (public) key for encryption. Symmetric key encryption techniques like the Advanced Encryption Standard (AES) use the same key to encrypt and decrypt data and asymmetric key encryption techniques use private and public keys (the public key is shared, but the private key is kept a secret to decrypt the information).

These encryption techniques rely on the fact that it will take a lot of computing power to crack the mathematical algorithms they are based on, with currently available systems. But with quantum computers becoming a reality, it is only a matter of time before these encryption standards become unsafe.

This is where Quantum cryptography comes in. A Stanford project on modern cryptography calls quantum cryptography as “the cutting edge discovery which seems to guarantee privacy even when assuming eavesdroppers with unlimited computing powers.”

One of the current challenges faced while transmitting data is how securely the encryption keys can be shared between the parties transmitting and accessing the data. Enter QKD.

“Today in most cases the security of the network is all in the software layers and this is because the backbone or the physical layer is assumed to be safe. But anybody can tap that network and QKD addresses that problem,” says Mathias.

QuNu Labs is currently privately funded and has 2 teams consisting of 12 people working at their Bangalore center and 10 others working at IIT-Madras. Their first QKD product, called the QNL-X100, is in its alpha prototype stage.

“The product is currently in its alpha prototype stage and is being readied for pilot trials, by the end of this quarter, with a few selected clients,” says Prabhakar. The clients also include defense labs in the country.

Some of the industries and sectors the company sees as their potential customers include defense establishments, intelligence agencies, financial institutions and corporates which handle confidential data.

Challenges for quantum systems

A big challenge for quantum technology implementations is that as the distance of the optical network increases so does the loss of photons or qubits (Quantum bits). Another challenge is to make the system work with an existing infrastructure and in some cases even if an existing optical link exists, it may bring down the efficiency of the system and hence a new optical link might need to be laid.

“The challenge with distance and length is being addressed by newer and more sophisticated protocols. Our initial prototype will have a range of up to 40 Kms and the next iteration is expected to go up to 200 Kms in range and the upgraded range can also be implemented on our existing model,” says Mathias.

Extreme environmental conditions can also pose challenges to such systems. For instance, photon detection works better at lower temperatures and in India, it tends to get hot. “Within closed labs, we can manage it better but in real-world deployments, you have to manage the environment,” says Prabhakar.

“The second challenge is the timing at which the photon has arrived. Photon arrival times are statistically unknown. If they are known then it is a security breach. So you need to be able to stamp the time on the photon and you have to do that with a certain amount of precision so that you have not confused it for another photon. How accurately are you able to derive that time stamp is another challenge.”

In the next three years, QuNu Labs also plans to foray into Post-quantum cryptography (PQC) Free Space, LiFi and Satellite-based QKD.

Companies like Toshiba and ID Quantique (IDQ) already offer QKD-based solutions but being an indigenous technology company might go a big way in helping QuNu Labs in the Indian market especially with applications in sectors like defense and security. The company is already in talks with defense establishments, DRDO and the Centre for Development of Telematics (C-DOT) for their product.