Hi folks ✌🏻 I see that concern about quantum threat became bigger and bigger with the Vitalik’s posts. Since this topic isn’t new (researchers for-seen this problem long time ago), right now we are staying on the point in time where we have to really be aware about it and think in a way, how to eliminate this problem.
At the time of writing this article, overall crypto capitalisation is 2 Trillion dollars 💵 , and i couldn’t imagine how easily it could collapse with the first quantum computer hack.
Part #1 - Quantum Computer
Let’s refresh our knowledge a bit. As we know, all info, seriously everything that is stored and processed in the computer and everything related to it, is done via bits (0, 1). Bits are the smallest unit of data, they are the basic building blocks of digital data storage, transmission, and processing in computers. Your tweet, photo, video , everything is represented in the bits.
On the other hand, we have the quantum computer, that uses qubits. A qubit is like a super-powered version of a regular computer bit. While a regular bit can only be 0 or 1 at any given time, a qubit can be both 0 and 1 at the same time! It's like being in two places at once. This is because of a cool quantum trick called superposition. So, instead of just having two options, a qubit can have a mix of 0 and 1, with different chances of being each one. To put qubits into superposition, researchers manipulate them using precision lasers or microwave beams.
It is also interesting to know about quantum computer that, when qubits interact with their surroundings, they can lose their special quantum abilities and go back to acting like regular bits. This process is called decoherence. Qubits are really sensitive, so even tiny things like vibrations or changes in temperature can mess them up. Scientists try to protect qubits from these outside influences by keeping them super cold and isolated in special chambers.
Quantum’s computer current abilities
In 2019, Google revealed its quantum computer cracked a tough problem in just 200 seconds. A regular computer would've needed around 10,000 years to do the same job. That's a huge difference!
To put it in perspective, the quantum computer was about 15.77 billion times faster and more powerful than a classical one. Pretty mind-blowing, huh?
But here's the exciting part: quantum computers are still evolving. They're going to become even more powerful and versatile in the future.
Experts predict it could take several years to a few decades for quantum computers to reach their full potential. Some say they could crack complex codes in less than 10 minutes by 2028! But others think it'll be more than 10 years before that happens.
Part#2 - Quantum computer and blockchain
I suppose that you are already familiar with you Asymmetric Encryption and RSA algorithm. If not, to simplify it, imagine that Public Key is login, that anyone one can see, and Private Key is password.
The main point here is: when user create an account the private key is generated and based on the private key the public key(that is visible to everyone ) is created. RSA algorithm exists in such way that if someone has your public key, he can’t derive your private key(password).
The threat that quantum computer poses is that just looking on someone’s public key, computer can “compute“ and derive the password(private key) from any account.
You could imagine like if there is a superhuman and just take a look at you could see all your passwords from bank accounts, everything, just from one look!
It sounds strange, but it is hot it is, and we should be ready to it, because there already exists two algorithm that could break Ethereum and Bitcoin using quantum computing.
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Shor's algorithm, made by Peter Shor in 1994, can quickly crack big numbers or solve tricky math problems like discrete logarithms. If it's used on a strong quantum computer, it could bust open a lot of today's encryption systems, like RSA and Elliptic Curve Cryptography, which depend on these tough math puzzles.
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On the flip side, there's Grover's algorithm, created by Lov Grover in 1996. It's a quantum search tool that can solve messy search problems. Grover's algorithm can weaken the security of symmetric encryption methods, but it's not unbeatable. Experts suggest doubling the length of encryption keys to counteract its power. While switching from AES128(encryption standard) to AES256(encryption standard) can help, it might not always work for every encryption method. As for hash functions, they're thought to be safe from Grover's algorithm, but there are cases where this isn't true.
Overall
In Buterin's contingency plan for a quantum emergency, the primary strategy involves implementing a hard fork, similar to the one executed by the Ethereum community following the DAO hack in 2016.
To execute this plan, Buterin proposed the creation of an Ethereum Improvement Proposal (EIP) outlining the steps for hard-forking the blockchain. Initially, the plan involves reversing illegitimate blocks to return stolen assets.
Subsequently, the new fork would suspend traditional transactions to prevent further exploitation of the hack. Instead, Buterin suggested introducing a new transaction type based on STARK proofs, which he believes would be resilient against quantum attacks.
Under this strategy, users would be required to download new wallet software, but the majority of users would not lose their funds, according to Buterin's conclusion.
While it's hard to predict when quantum computers will crack encryption, it's clear we're not there yet. There's still time to prepare before it becomes a real threat. We have solutions like post-quantum cryptography, but the crypto industry needs to take action and invest in them. Keeping an eye on quantum advancements is crucial. We're expecting new secure elements to emerge for hardware, and we need to stay updated on the latest algorithm developments to ensure reliable encryption for users.
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