What happens when quantum computers develop into a reality?
One of my favorite moments at a cryptocurrency seminar last 12 months was when someone asked this query. The answer was dead silence. After an extended pause, the speaker said something like, “We’ll find out when we get there.”
Let me explain.
The entire premise of blockchain technology and the cryptocurrencies, non-fungible tokens (NFTs) and smart contracts built on it’s that distributed ledgers are extremely secure and can’t be hacked using modern computers. I’m simplifying it a bit, but for a transaction to be accepted by the blockchain, greater than 50% of the computers on the network sharing the blockchain must agree that the pc claiming to be the brand new owner of a cryptoasset has it is definitely the rightful owner. And the network only accepts claims which have Proof of Work (PoW), which is actually an enormous multiplication of several very large numbers. Again, I’m oversimplifying this.
Once such a PoW is submitted to the blockchain network and greater than 50% of computers accept it, a brand new block is added to the chain and the longer blockchain is taken into account the true blockchain. Submitting a PoW for a brand new cryptocurrency creates a brand new token or coin. Likewise, filing a PoW creates a contract that proves ownership of specific assets without counting on centralized databases or potentially corrupt government officials.
Now imagine with the ability to produce these PoWs faster than all of the computers on a network can confirm the accuracy of the PoWs. Then you could possibly always escape the verification process and generate latest blocks on the blockchain before the remainder of the network could confirm them. And since every blockchain technology assumes that the longest blockchain is the legitimate one, you could possibly effectively “hack” the system. All other computers would simply accept your blockchain because the one against which they may compare each latest PoW.
With modern computing power, it is solely unimaginable to create such a so-called 51% hack. But quantum computers will likely be a lot faster that they are going to eventually easily outpace any network of conventional computers. In fact, speed won’t be their only advantage.
Conventional computers are based on transistors that distinguish between two binary states – so-called “bits” – 0 and 1. However, quantum computers can take each 0 and 1 at the identical time and superimpose these “Qbits”. If that sounds strange, consider a typical old-fashioned computer that encodes letters or numbers as a sequence of eight bits. There are 256 different characters or numbers that might be encoded with these eight bits, and at any given time a transistor in a normal computer is in one in every of these 256 possible states. But a quantum computer with eight Qbits could assume all 256 states directly and use them for calculations at the identical time. The advantage of quantum computers grows exponentially the more Qbits they contain.
This signifies that algorithms in quantum computers should be completely redesigned to benefit from these computing capabilities. But it also signifies that quantum computers will likely be far more powerful. They will easily solve problems that traditional computers couldn’t solve within the remaining lifespan of the universe.
So as an instance you were the primary person or company to construct a totally functional quantum computer. Since all networks on the earth are based on traditional computers, one could adopt any blockchain on earth in a matter of seconds. Only when nearly all of computers in a network develop into quantum computers will the blockchain be secure again. But by then it is perhaps too late.
This advantage of quantum computers holds even when she have not likely achieved what known as a real quantum advantage, or in the event that they can solve problems that no conventional computer can solve. Once the problem-solving capability of ordinary computers becomes far enough superior to their quantum counterparts, all the world’s blockchains might be hacked by anyone with a quantum computer.
So if quantum computers develop into a reality, blockchain technology can have to be completely recreated or they are going to lose all of their decentralization and security advantages.
But quantum computers are still just science fiction, right? Yes they’re. But they’re currently being developed. And while you extrapolate current progress Based on Moore’s Law, a single quantum computer will have the opportunity to hack the Bitcoin blockchain by around 2045.
Quantum computing vs. Bitcoin hash rate
And this estimate is predicated on two assumptions: First, that quantum computing is advancing at the identical pace as traditional computing. However, we all know that latest technologies are likely to progress much faster than established ones. Second, the 2045 date applies to the Bitcoin blockchain, which is by far essentially the most complex and computationally intensive. (This is why Bitcoin as a payment system cannot compete with the PayPals and bank card networks of the world). Other blockchains equivalent to Ether or the underlying business applications use much smaller networks. And in response to a brand new study on the advantages of quantum computers, quantum computers could hack such blockchains as early as 2023.
Personally, I don’t think 2023 is realistic. But the more I examine advances in quantum computing, the more I consider it could occur sometime this decade. And what happens then?
Unless all blockchain applications are fundamentally redesigned prematurely, they’re prone to develop into insecure and unusable.
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