Research in quantum information science has indicated that large-scale quantum computers could end up rendering most of today’s encryption techniques as insecure. Although a large-scale quantum computer is still some time off, the situation is nevertheless seen as needing a response. As a result, two broad directions have been pursued globally, namely a software-based approach called post-quantum cryptography and a hardware-based approach called quantum cryptography.
Post-quantum cryptography looks to update existing cryptographic algorithms and standards so that current infrastructures would be ready for a post-quantum digital world. It however maintains a security profile that is still based on many unproven assumptions. Quantum cryptography, by contrast, offers a much stronger security guarantee: its security is solely based on the laws of quantum physics and is, in principle, unbreakable.
As such, it is regarded in terms of critical information infrastructures with long-term security needs such as healthcare, government and banking, quantum cryptography as the safer way to go. QKD systems are being developed in many countries, most notably in Austria, Canada, China, Japan, South Korea, Switzerland, the U.S., as well as the UK.
With this approach, two essential building blocks are quantum key distribution (QKD) and quantum random number generation (QRNG). At present, however, the methods and processes enabling these quantum technologies are limiting and very expensive. Consequently, these bottlenecks have made quantum cryptography unattractive for wide-spread deployment.
Commercially viable QKD transmitters and receivers are available—however, they are physically large and expensive, and only suitable for very high-value security applications. The aspiration of the industry is to address these size, weight, and power (SWaP) limitations, to deliver practical quantum-secured communications that will open broader markets for consumers, commerce, and government. Other methods of implementing QKD are being rapidly developed, including those based on encoding information into the phase of multiphoton pulses, as well as systems based on entangled photons.
Challenges of QKD chips on Mobiles
Currently the most practical and commercially advanced QKD systems use single photons that are created by attenuating laser pulses. Originally developed as modules fitting into 19-in. racks, chip-scale prototypes have been recently developed, offering low SWaP consumption and the potential for integration into consumer electronics.
One of the breakthrough technology for minitiarization of QKD systems is Photonics as it uses photons (smallest unit of light) as the data carrier instead of electrons (smallest unit of electricity) used in electronic ICs. As light travels at very high speeds, photonics is widely used to transfer huge amounts of data at a very high speed.Thus photnics based products are primarily deployed in the field of optical fiber & optical free space communications.
Just as Integrated circuit (IC) is a microelectronic device that houses multiple electric circuits on a chip, a photonic integrated circuit (PIC) or Integrated Photonic circuits (IPC) are devices that integrate multiple photonic functions on a chip. A typical IPC may consist of single photon sources, nonlinear photon processing circuits and photon detectors all integrated onto a solid-state chip. Photonic integrated circuits (PICs) have attracted considerable attention owing to their small footprint, scalability, reduced power consumption and enhanced processing stability.
A major step towards SWaP-saving is to engineer QKD on affordable chips, such as those that will fit into a smartphone. The physics is proven, but the challenge is developing small-enough devices. For transmitters, photon sources at chip-scale have been successfully developed using light sources with filters to control production of single photons. These provide workable devices for current commercial QKD. However, further photonics challenges remain, particularly around chip-scale entangled photon generation for alternative approaches to QKD.
Detectors are more challenging since materials sensitive enough to detect single photons are bulky. The best current detector materials are superconducting—requiring significant cooling apparatus. However, detector size is less of an immediate problem since early QKD would likely involve a secure end-user location—such as a bank or government department—that could accommodate a bulkier detector. But the long-term goal is smaller detectors so that laptops can communicate directly with each other, pointing towards semiconductor devices.
Imec and NUS to collaborate on chip-based quantum cryptography technology
Imec, the research and innovation hub in nanoelectronics and digital technologies, and the National University of Singapore (NUS) have signed a research collaboration agreement to develop chip-based prototypes for secure quantum communication networks. As part of this five-year agreement, imec and NUS will jointly develop scalable, robust and efficient technologies for quantum key distribution and quantum random number generation, which are amongst the basic building blocks of a secure Quantum Internet.
Together, imec and NUS will be looking to resolve some of these bottlenecks, leveraging on the theoretical, experimental and engineering expertise of their respective R&D teams. The overarching objective is to move QKD and QRNG technologies to a platform which is much more scalable, robust, and cost-effective. The research collaboration is supported by the National Research Foundation Singapore under the Quantum Engineering Programme.
“Our approach consists of developing and integrating all QKD key components in a single silicon-photonics based chip, which ensures a cost-effective solution,” said Joris Van Campenhout, R&D Program director at imec. “As a first deliverable, we will jointly develop an ultrafast quantum random number generation (QRNG) chip, a key component for generating the secret keys.
“Secondly, we will work on a compact, fully-integrated photonic quantum transmitter prototype chip. In these efforts, we will strongly leverage imec’s deep expertise in silicon photonics technology, originally developed for conventional datacom and telecom applications.” Dr. Charles Lim, Assistant Professor at NUS said: “The development of chip-based prototypes will allow us to turn today’s QKD technologies into an efficient communication networking solution. Our team at NUS will bring in expertise on the theory, protocol design, and proof-of-concept experiments of the quantum random number generator and QKD systems. We’re very excited to collaborate with Imec, as their expertise will allow us to translate these solutions into real silicon-photonics based chips – by using imec’s process design kits and re-usable IP blocks.”
New chip-based devices contain all the optical components necessary for quantum key distribution.
A research team at the University of Bristol has demonstrated chip-based devices that contain all the optical components necessary for quantum key distribution (QKD). The team showed that secure quantum key exchange could be accomplished between two chip-based devices measuring just 6 × 2 mm over a fiber network with links up to 200 km. The researchers used mass-manufacturable, monolithically integrated transmitters to demonstrate their accessible, quantum-ready communication platform. The new QKD devices are based on the same semiconductor technology found in smartphones and computers. Instead of wires to guide electricity, they contain circuits that control the photonic signals necessary for QKD. Nanoscale components in the chips make it possible to reduce the size and power consumption of QKD while maintaining high-speed performance.
The researchers designed the new platform to facilitate citywide networks and decrease the number of connections required between users. “Our platform allows single users to connect to a centralized node that enables secure communication with every other user,” researcher Henry Semenenko said. “As quantum networks develop, the centralized node will offer crucial infrastructure that will eventually support more complex communication protocols.” The researchers demonstrated their new chip-based devices with a proof-of-principle experiment in which they emulated a 200-km fiber network at the University of Bristol Quantum Engineering Technology Labs. Using two independent chip devices, they showed that error rates and speed were comparable to state-of-the-art commercial components.
“We showed that these chip-based devices can be used to produce quantum effects even when photons were generated by different devices,” Semenenko said. “This is vital for quantum networks where each user will control their own devices that are distributed around a city.” The researchers plan to make the system more practical by developing application-specific hardware. They will then use the fiber optic network in place around the city of Bristol to create a model metropolitan network with many users. “With its densely packed optical components, our chip-based platform offers a level of precise control and complexity not achievable with alternatives,” Semenenko said. “It will allow users to access a secure network with a cost-effective device the same size as the routers we use today to access the internet.”
Samsung and SK Telecom reveal world’s first smartphone with quantum security tech
Samsung and SK Telecom unveiled in May 2020, the world’s first 5G smartphone with a Quantum Random Number Generator (QRNG). Called the Galaxy A Quantum, the device (which is essentially a rebranded Galaxy A71 5G) offers some pretty decent smartphone features, but the QRNG sets it apart from others in that it makes some apps and services much harder to hack.
Normal random number generators are used for logging into a variety of smartphone services, such as payment platforms and two-factor authentication, which are routinely targeted by bad actors as they can be bypassed. The QRNG chipset, however — the world’s smallest at just 2.5mm by 2.5mm — instead uses an LED and CMOS image sensor. The LED emits “image noise” and the CMOS sensor captures its quantum randomness, using these unpredictable patterns to create truly random number strings. According to SK Telecom, there’s no tech out there that can hack this, which makes the Galaxy A Quantum one of the securest phones on the market (although it’s worth noting that the chip — aka the SKT IDQ S2Q000 — has been designed for use exclusively with SK services).
The QRNG chip found in the Samsung Galaxy A Quantum is provably random, has full entropy from the first bit, and has been both designed and manufactured specifically for mobile handsets. The quantum randomness is achieved by way of “shot noise” from a light source captured by a CMOS image sensor. A light-emitting diode (LED) and an image sensor are contained within the chip, and that LED emits a random number of photons thanks to something called quantum noise, ID Quantique explains. Those photons are then captured and counted by the image sensor pixels and provide a series of random numbers fed into a random bit generator algorithm.
The algorithm further distills the “entropy of quantum origin” to create the perfectly unpredictable random bits. If any failure is detected during the physical process, the stream is disabled and an automatic recovery procedure starts another. With uses such as two-factor authentication, biometric authentication for mobile payments, and blockchain-based document storage wallets, the QRNG will be put to good use.
Grégoire Ribordy, co-founder and CEO of ID Quantique, said, “With its compact size and low power consumption, our latest Quantis QRNG chip can be embedded in any smartphone, to ensure trusted authentication and encryption of sensitive information. It will bring a new level of security to the mobile phone industry. This is truly the first mass-market application of quantum technologies.” Ryu Young-sang, vice-president at SK Telecom, said the Galaxy A Quantum is a “new chapter in the history of the quantum security industry.”
Smartphone equipped with quantum technology
South Korea’s SK Telecom announced in April 2021, the Galaxy Quantum2, its second smartphone featuring quantum cryptography technology. The Galaxy Quantum2 includes the world’s smallest quantum random number generator (QRNG) chipset that enables trusted authentication and encryption of information. Thanks to the native integration of the QRNG chip into the Android Keystore (APIs), this smartphone improves the security of a large number of services used on the smartphone.
The chip encrypts codes by true random numbers, creating secure keys with unpredictable patterns. The new smartphone fitted with quantum cryptography is evaluated as the highest level of security that cannot be hacked with any of today’s technology, according to the company. It is ahead of iPhone’s security that relies on an ordinary random number generator that creates complex patterns.
The chipset is applied to two-factor authentication for T-ID, biometric authentication for the SK Pay mobile payment service, and Initial, a blockchain-based mobile electronic certification service. T-ID, which uses ID login and quantum one-time password (OTP) authentication, is applied to SKT’s 28 services including online marketplace 11st, mobile navigation T Map, OTT platform Wavve, music streaming FLO, T Membership and AI speaker Nugu. Users will also benefit from advanced security protection while making payments via the SK Pay app at offline retailers.
Initial automatically creates a ‘quantum wallet’ when users store their personal certificates such as graduation certificate and insurance claim documents, providing an added layer of security. The Galaxy A Quantum features a 6.7-inch Super AMOLED Infinity-O display and a 4500mAH battery. It is priced at 649,000 (about $530).
“With the Galaxy Quantum2, we have successfully expanded the application of quantum security technologies to a wider variety of services including financial and security services,” said Han Myung-jin, Vice President and Head of Marketing Group of SKT. “Our efforts will continue to keep expanding services that are safely and securely provided via the Galaxy Quantum2.”
References and Resources also include: