Pratima Harigunani
Quantum Computing’s big-bangs are translating into new whispers in the Blockchain world. Let’s check out if computational cylinders were the only thing Blockchain attackers needed all this time to crash into the might and muscle of this technology
Mathematics – that one answer for anyone who is asking why the hashing and mining of cryptocurrency were made to be mistake-, accident- and attack-proof. Satoshi’s block system hinges solely on the huge chunks of time, the complexity underneath and the heaviness of effort that one would need to make a dent here. Also, the computational horsepower that would have been needed to slip into this water-tight system – another deterrent crafted ingeniously deep inside the chain.
But 2019 changed that or threatened to, at least. Just like Moore’s law confronted the realities of chip geometries shrinking, the in-built strengths of first-generation Blockchain systems had to meet their obits. Quantum Computers came in as the Graphene moment for Crypto last year. As Google and IBM started jostling for the ‘Numero Uno’ plank in the race of Quantum Computing (QC), a spill-over was bound to happen for blockchain players.
Can we assume that huge bulldozer has finally arrived here – capable of crumbling every complexity and resource-wall that Blockchain thrived on? After all, quantum computers HAVE to be quantum. They can crunch endless miles of computational problems like a potato chip that disappears inside a giant’s mouth.
T-Rex or I-Rex? Silicon or Germanium?
Gautam Kapoor, Partner, Deloitte India prefers to not put Quantum Computing into a box of good-bad yet. Although he avers that now Quantum computers designed for that purpose, the classic encryption methods, especially those that rely on near impossible mathematical problems, are at risk of being broken easily. “Quantum computers of 4000 Qubits would be able to achieve that by around 2023.”
Vidit Baxi, Co-founder, Lucideus attributes the advantage edge of QC on the possibility of multiple states instead of an either 0 or 1 state seen so far. “The variable has multiple states at the same time and hence the number of functions executed in parallel is exponentially higher than a conventional computer.” Consider how asymmetric algorithms were extremely difficult, as it took an astronomically-large number of calculations to factorize an integer. Things could change with the likes of a quantum computer algorithm.
Shor’s algorithm is a case in point, Baxi reasons. It can successfully factorize small integers in record time (using 5-15 QBits). In fact, even in theory, if we are able to run Shor’s Algorithm on a Quantum Computer with millions of qubits, that could make it quite easy to break most of the asymmetric Algorithms. Baxi does say the dreaded word. “Most cryptocurrencies, too, would cease to exist in such a scenario.”
There’s still time, baby
Andrew Myers, Professor in the Computer Science Department, Cornell University, does not expect Quantum Computing in the short-term to have much impact on the blockchain industry. “Quantum Computing can, in principle, be used to break the security of current blockchains like Bitcoin, but it will take a much larger quantum computer than currently exists. It will be at least 10 years and probably more before building such a computer is feasible.”
Just like how Kapoor opines that these giant computers would take some finite time to break encryption. Meanwhile, the industry should get busy developing quantum-resistant cryptography and quantum key distribution. As Baxi cites, new-age Lattice-based crypto algorithms are in progress and they will not be dependent on the assumption of integer factorization. They can turn out to be quantum computing-proof to a large extent.
Interestingly, IBM also contends something similar when it challenges Google’s claims on Quantum Supremacy. IBM’s research think-tank takes us back on the original meaning of the term ‘quantum supremacy’ – the point where quantum computers can do things that classical computers can’t. This threshold, they maintain, has not been met. IBM’s team compliments Google, but with a pinch of salt and pepper. “Google’s experiment is an excellent demonstration of the progress in superconducting-based quantum computing; showing state-of-the-art gate fidelities on a 53-qubit device, but it should not be viewed as proof that quantum computers are “supreme” over classical computers.”
Saddle Up
There is a long-horizon to get wary and ready for- nonetheless. Professor Myers argues that current blockchains are – in the long- run – vulnerable because they rely on Elliptic-Curve Cryptography (ECC) to allow users to prove who they are. “Blockchains will eventually switch to lattice-based cryptography for this task because although lattice-based cryptography is much more expensive, quantum computing cannot break it.”
So the big creature may still be a forest away but if we can hear his trumpet already, it’s better to get ready. Don’t we know two strange facts about elephants? First, they may not be able to jump, but they swim pretty well. Second, the baby can stand up shortly after being born!
How ‘shortly’ this time, let’s not find out the hard way.
