Can Quantum Computers Hack Bitcoin? Is It Real

Hello! One of the hottest tech topics these days is quantum computing. Since Google announced Willow, its newly developed quantum chip, people have been asking, "Isn't Bitcoin going to get hacked too?" Is that really true?

So far, Bitcoin has been known to be safe thanks to blockchain technology and its own security system. Today, we'll look at whether quantum computers could actually hack Bitcoin, and what countermeasures are being prepared for the future.

Is Bitcoin really safe?

The reason Bitcoin has stayed safe and almost impossible to hack comes down to two powerful security technologies.

1. Digital Signatures (ECDSA)

Even the name sounds difficult. Strictly speaking, it's ECDSA (Elliptic Curve Digital Signature Algorithm), and put simply, it's a technology that protects your money using two keys: a private key and a public key. In short, you can think of it as the key to your Bitcoin wallet.

• Private key: The "secret key" that opens your wallet. It's like a "safe key" that only the wallet owner should know.
• Public key: A "public key" that anyone can see. It's used to verify that a transaction is genuine.

To sum up, when you send a crypto asset like Bitcoin, you sign the transaction, right? Breaking that process down a bit more, 1) you sign with your private key, and 2) it's verified with your public key.

Bitcoin uses this kind of digital signature algorithm to process transactions and protect users' assets. The bottom line is that, as things stand, as long as you keep your private key and mnemonic phrase safe, the chance of your assets being stolen is close to 0%. In other words, Bitcoin is safe.

2. SHA-256 Hash Function

The second technology is called SHA-256. In a word, it's one of the technologies used to encrypt data.

• All of Bitcoin's blockchain data is encrypted with SHA-256.
• The key point is that with the SHA-256 algorithm, even a tiny change in the data produces a completely different hash value, so if anyone tries to tamper with it, it shows right away.

Proof of Work, which miners use, also relies on SHA-256 and repeats an enormous amount of computation, so it can't be broken easily without a massive effort.

So, can quantum computers hack Bitcoin?

You might be wondering: if Bitcoin is so safe, why is everyone making such a fuss about quantum computers? The thing is, quantum computers compute in a fundamentally different way from conventional computers. If a regular computer "calculates one thing at a time," a quantum computer "calculates everything at once."

Put like that, you might think, "So what? That's no big deal," but in reality their computing power is so staggering that people are saying it could pose a threat even to Bitcoin's security technology.

1. Shor's Algorithm: A Technique for Cracking Private Keys

Shor's algorithm, which can run on quantum computers, is an algorithm that can work backward to calculate Bitcoin private keys. And if it succeeds? Someone could steal your private key and wipe out every bitcoin in your wallet.

Realistically, though, there's no need to worry yet. Why? To properly use Shor's algorithm, you'd need millions of qubits. With today's quantum computing technology, that level of performance is nowhere near possible. Even Google's Willow chip has a mere 105 qubits.

2. Grover's Algorithm: Weakening Hash Functions

Grover's algorithm is a technique that could weaken Bitcoin's SHA-256 hash. It can carry out brute-force attacks much faster.

But here's the thing. Grover's algorithm only weakens SHA-256 by "about half." Even cut in half, finding a hash value still requires an enormous amount of computing power. Today's Willow chip doesn't come anywhere close.

Still... the Bitcoin network is preparing for attacks

"Still, you never know what the future holds, so we should be prepared!" That's how Bitcoin developers see it. So several countermeasures are being discussed.

1. Adopting Quantum-Resistant Cryptography

New encryption technologies that are safe even against quantum computer attacks are being developed. The U.S. National Institute of Standards and Technology (NIST) has been running a post-quantum cryptography standardization project since 2016, and in 2022 it also announced its final candidate algorithms. There's a good chance the Bitcoin network will adopt technologies like these.

2. Flexibility of the Bitcoin Protocol

Bitcoin's creator, Satoshi, designed the protocol with the future in mind. If problems ever arise with SHA-256 or ECDSA, there's an option to upgrade to a different encryption method. In other words, Bitcoin is ready to evolve as technology changes.

3. Minimizing Public Key Exposure

Because of how Bitcoin transactions are structured, the public key is only exposed on the blockchain after the transaction is complete. This means that even if a quantum computer tried to calculate the private key, there would be almost no time to actually carry out an attack.

So, what's the conclusion?

There's no need to worry right now! Hacking Bitcoin with today's quantum computers is close to impossible. Experts predict it will take decades before quantum computers with millions of qubits appear. Above all, that leaves Bitcoin plenty of time to upgrade and put security measures in place.

In conclusion, the idea that "quantum computers will hack Bitcoin" is, for now, not something you need to worry about.