The end of 2018 saw Trump signing a legislation to boost quantum computing research and development. The National Quantum Initiative Act will authorize $1.2 billion over five years for federal activities aimed at boosting investment in quantum information sciences, signifying its importance in the future of national security.
While the quantum approach is particularly well-suited to certain types of tasks, there are risks where a powerful quantum computer could conceivably crack the code that currently protects secure communications and financial transactions. This means there is an urgency to develop post-quantum encryption protocols in order to protect national security.
To gain further insight into these risks Digital Journal spoke with cryptography expert Shlomi Dolev, Professor of Computer Science at Ben Gurion University and CSO of Secret Double Octopus.
Digital Journal: What will the National Quantum Initiative Act achieve?
Shlomi Dolev: The Quantum Initiative Act will direct resources to support the education, research and development of Quantum information and computing. The Act will also establish a US quantum coordination office under the US Department of Science and Technology, to promote collaborative efforts between federal agencies and private research groups.
DJ: What’s the driver behind the Act?
Dolev: Similar to the nuclear arms race in the 1950’s, the scientific and technological race in quantum computing and quantum information is accelerating, as nations begin to recognize the power of Quantum information and computing as crucial for their economic, governmental and defense capabilities. Quantum computing promises to do many things for business and industry, processing data at far greater speeds and rates than today’s binary computers can accomplish.
Recently, China has been able to transmit entangled qubits from space, which in turn can serve as a means for quantum key distribution and secure encryption between remote end-points (much more than the previous limit of 100km) e.g., Ji-Gang Ren et. al “Ground-to-satellite quantum teleportation,” Nature, volume 549, pages 70–73 (07 September 2017)
With China being the first country to reach this goal, the pressure is now on the other hopefuls vying to be the nation to emerge as the world leader in quantum computing.
DJ: What has prompted President Trump to back this legislation?
Dolev: There are a lot of competitors vying to be the world leader in the quantum technology sector. In an effort to be the ultimate authority, President Trump’s legislation could not come at a more crucial time, as other countries, like China and Russia, continue to make breakthroughs in quantum development.
DJ: How advanced is quantum computing?
Dolev: The emergence of quantum computers is a fact, the number of qubits is a major criterion for quantum supremacy over legacy high performance computing centers. The race among vendors for providing commercial quantum computers started with the commercial several thousand qubits of DWave provided for specific applications. Recently, several leading companies, including IBM, have commercialized 50 qubits quantum computers. The quantum computers race has led to exponential growth in the number of qubits.
In fact, last year Intel presented a 49 qubits quantum computer and Google announced 72 qubits computers. Additionally, several startups, including Rigetti, IonQ and qci, have announced 36 qubits quantum computers and a Quantum Processing Unit (QPU).
Many Quantum computers employ qubits teleportation — which is the way to transfer qubits from one location to another — to allow quantum operations over any pair of quantum bits. The advancements in techniques for producing entangled qubits and teleportation may assist in using several quantum computers to cooperate on a task by teleporting qubits from one to the other. Thus, yielding a virtual quantum computer with the needed qubits for a task, specifically, for breaking RSA, much earlier than estimated.
DJ: What are main obstacles that need to be overcome?
Dolev: The main obstacle that needs to be overcome surrounds the physical signal noise, which can yield unstable states. This is the reason why cooling to almost the absolute zero is essential. Typically the entire quantum processor needs to be cooled, but room temperature devices with laser cooling effects, like imperfect diamonds, are also being developed.
DJ: What is quantum computing best suited for, in terms of encryption?
Dolev: Quantum computing is best suited for breaking current encryption or revealing stored communication from the past, just as Peter Shor’s quantum algorithm is designed to do. Once enough qubits exist in one computer (or in several) that can teleport qubits amongst themselves, the decryption becomes easy. On the positive side, quantum key distribution may form a secure alternative for establishing a common symmetric key.
DJ: Which sectors will benefit most from quantum computing?
Dolev: Biology, chemistry, physics and the like will use quantum computers to simulate quantum phenomena in reasonable time. AI and search algorithms may speed up by using Grover’s algorithm and other algorithms like his. Contrary to popular belief, many new quantum applications and algorithms are being designed daily, and many can be found on Shor’s ‘Quantum Algorithm Zoo’ website which cites 262 papers on quantum algorithms. Additionally, encryption will greatly benefit from quantum computing by way of quantum key distribution. While quantum computers could conceivably crack encryption codes as we know them today, quantum key distribution effectively addresses these challenges by providing a provably secure cryptographic building block for remote parties to share cryptographic keys.
DJ: Are there risks that quantum encryption can be cracked?
Dolev: Quantum encryption has several meanings. One is quantum key distribution (QKD) that uses high probability to sense is whether someone eavesdropped during the key distribution. This technique is currently used in ranges for up to 100km fiber optics that connect participants in a point to point fashion. This solution is limited, as once a key is established between two endpoints, there is still the challenge of forwarding clear-text in multi-hop channels. For example, China is using satellites to enlarge the distance restriction, and still the multi-hop case is challenging.
Another approach in the scope of quantum encryption is the search for one-way-functions that are not known to be broken by Quantum computers, unlike RSA, which has been predicted will be broken by Shor’s algorithm once a strong enough Quantum computer exists. There are a few candidates, believed to be one-way-functions, (intuitively, a toy intuitive example of one-way-function is squaring a number that is easy, while the reverse square root seems harder) to become alternatives to RSA, but have not yet proved that they are qualified to be one-way-functions. As there is no proof for the existence of one-way-function, these functions risk the existence and (maybe already unpublished) discovery of an algorithm that will reverse the function.
