via Forbes : Quantum computing may still largely reside in the realm of scientists, but assuming it’s too many years off to be relevant today would be a serious mistake.
In reality, quantum computers are now commercially available. The research has largely exited the pure science phase and is now focusing on resolving engineering challenges.
Furthermore, progress continues at an exponentially accelerating pace, extending Moore’s Law well beyond traditional semiconductor-based microprocessors.
But the real reason you should pay attention: quantum computing can – in theory – defeat all modern encryption. From secure banking transactions to confidential correspondence to, yes, Blockchain – quantum computing can crack them all quickly and simply.
One more thing: don’t let my ‘in theory’ caveat provide any comfort. Theory is well on its way to becoming cold hard reality, sooner than you realize.
Why Factoring Big Numbers is a Big Deal
Any computer can easily multiply two large prime numbers together – but taking the product of two such primes and factoring it is wicked hard. Such asymmetry is at the core of all modern key-based encryption.
Encrypting data is easy while decrypting them without the key could take years, depending upon the length of the key.
However, back in 1994, long before quantum computing was anything but pure theory, mathematician and MIT professor Peter Shor created a quantum algorithm for factoring large numbers far more quickly than conventional computers could.
Today, Shor’s Algorithm remains the bar every quantum computer aspires to. “Shor’s algorithm was the first non-trivial quantum algorithm showing a potential of ‘exponential’ speed-up over classical algorithms,” explains Mark Ritter, Senior Manager at IBM IBM -0.22% T.J. Watson Research Center. “It captured the imagination of many researchers who took notice of quantum computing because of its promise of truly remarkable algorithmic acceleration. Therefore, to implement Shor’s algorithm is comparable to the ‘Hello, World’ of classical computing.”
Today, we’re already moving past Shor’s ‘hello, world.’ “We show that Shor’s algorithm, the most complex quantum algorithm known to date, is realizable in a way where, yes, all you have to do is go in the lab, apply more technology, and you should be able to make a bigger quantum computer,” says MIT professor Isaac Chuang.
Building a Bigger Quantum Computer
And building bigger quantum computers is just what this nascent industry is focusing on. At the Russian Quantum Center (RCC or RQC) International Conference on Quantum Technologies (ICQT-2017) last month in Moscow, Harvard professor and RCC co-founder Mikhail Lukin presented results that shook up the conference – as well as the industry at large.
His announcement: his team had successfully created a 51-qubit quantum computer of a type that can –again, in theory – execute general computations.
“Lukin’s team has already solved several physical problems, extremely difficult to model with the help of ‘classical’ supercomputers,” according to a conference press release (translated from Russian by Google Translate). “To verify the results of these calculations, Lukin and his colleagues had to develop a special algorithm that allowed similar calculations to be performed in a very crude form on ordinary computers. The results on the whole coincided, it confirmed that the 51-qubit system of scientists from Harvard is working in practice.”
Today, Lukin’s quantum computer can only execute Shor’s algorithm for small numbers – but what the results show is not only that factoring large numbers is possible, but that reaching the ability to defeat all modern encryption is now within the grasp of the technology.
The True Impact of Defeating Modern Cryptography
The fall of modern cryptography would disrupt the economy as well as the balance of power across nation states – a fact not lost on researchers. “Quantum computer technologies can’t be hacked, and in theory, its processing power can break all encryption,’ says Cybersecurity expert Larry Karisny, director of cybersecurity think tank ProjectSafety.org. “The computational physics behind the quantum also offer remarkable capabilities that will drastically change all current AI and cyberdefense technologies. This is a winner-takes-all technology that offers capability with absolute security capabilities — capabilities that we can now only imagine.”
Clearly, the United States National Security Agency (NSA) – along with its counterparts in Russia and elsewhere – have a vested interest in defeating encryption across the globe. However, the excitement and its concomitant funding and research support isn’t only interested in breaking today’s cryptography.
In fact, much of the effort is now focusing on developing next-generation cryptography that is ‘quantum-proof.’ “The goal of post-quantum cryptography (also called quantum-resistant cryptography) is to develop cryptographic systems that are secure against both quantum and classical computers and can interoperate with existing communications protocols and networks,” according to the US Department of Commerce’s National Institute of Standards and Technology (NIST). “NIST has initiated a process to solicit, evaluate, and standardize one or more quantum-resistant public-key cryptographic algorithms.”
Researchers are making good progress on post-quantum cryptography, largely due to the principle of quantum entanglement, a way of establishing communication between two parties that is absolutely unhackable – once again, in theory.
Secure communications are important in many contexts. For example, given the level of excitement (some would say ‘hype’) over Blockchain, it’s no surprise that some researchers have latched onto a new technique called quantum key distribution to build quantum secure Blockchain interactions.
Evgeny Kiktenko at RCC is pursuing this line of research. “We have developed a blockchain protocol with information-theoretically secure authentication based on a network in which each pair of nodes is connected by a quantum key distribution link,” he and his coauthors say.
Such research into post-quantum cryptography, however, is far behind the progress of quantum computers themselves. Furthermore, the progress Kiktenko and others have made focuses solely on securing interactions between parties, but doesn’t address the security of data at rest.
As such, researchers are still at a loss to provide comprehensive quantum-level security to Blockchains, as nobody knows how to protect the chains themselves – or any other data stored anywhere on the planet.
The Window of Opportunity – or of Chaos
Post-quantum cryptography promises to be on the drawing board for years, but quantum computers are already arriving. IBM, for example, says its quantum computers are a few years away. “That doesn’t mean a lot of years,” points out Scott Crowder, CTO and Vice President for Quantum Computing, Technical Strategy and Transformation, IBM Systems at IBM. “It really means soon. We’re at the cusp.”
Furthermore, one vendor – D-Wave Systems – has been delivering one generation of quantum computer after another for a few years now. Its latest model has 2,000 cubits, and they’ve actually sold at least one of them. (See my 2015 article on D-Wave Systems.)
The D-Wave quantum computers, however, take a different approach from the one Lukin’s team came up with. They solve a narrower set of problems and require more qubits than Lukin’s does for similar problems.
Nevertheless, the D-Wave systems are the only commercially available quantum computers on the market today – an important milestone. “Others are trying to do what may be a more mathematically or theoretically pure version of quantum computing, but they are years away from even solving simple problems,” says D-Wave CEO Vern Brownell. “We’re the only ones that have real customers.”
Furthermore, in spite of the narrower scope of problems D-Wave’s computers can solve, theoreticians have shown that they can execute Shor’s algorithm nevertheless – again, in theory.
One important caveat for D-Wave’s systems as well as every other quantum computer under development: they require near-absolute zero temperatures, making them expensive and difficult to operate.
However, researchers are hammering away at this limitation as well. “Researchers are currently seeking platforms that permit manipulating quantum states in room temperature conditions,” according to Alexey Kavokin of the RCC and Professor at the University of Southampton in the UK. “In some 3-4 years’ time, we can demonstrate a room-temperature quantum simulator with several hundred nodes.”
Given the accelerating pace of innovation in this space, three years may be on the high side – and before we realize it, we may have affordable quantum computers on our desktop, or even in our pocket.
How long it will take to replace modern cryptography with the post-quantum alternative, however, is anybody’s guess – and there is certain to be an interval of several years where the world has no effective cryptography.
Criminals are unlikely to be able to afford to purchase or run quantum computers during this interval, but nation-states are another matter. Given how badly the US is losing the cyber war to Russia, it’s no surprise Russia is at the forefront of quantum computer research.
Should the Russian government break all of our encryption before the US develops countermeasures, stolen elections will seem like small potatoes. Welcome to the cyber-battlefield of the 21st century.
Source : Forbes | This Is Why Quantum Computing Is More Dangerous Than You Realize