Are Quantum Computers Hacking Bitcoin?

by: Block_Editor

Two years ago, articles often predicted that quantum computers could hack Bitcoin by the end of 2022. Since the time has arrived, we are revisiting the question to assess the state of quantum hacking of crypto.

To answer the question, we interviewed former Cryptography Scientist T.Y, the head of DRepublic Labs and founder of Cradles.io. T.Y gave a brief overview of quantum computing to help explain the concept to us plebs. He started by explaining that quantum computing can threaten the Bitcoin network. He followed up by stating it might be possible to harm Ethereum but not as likely. With the successful merge happening just hours after this interview, this news should be comforting to ETH maxis far and wide.

Bitcoin and Ethereum both use a private and a public key. When using encryption to sign a transaction, those encryption algorithms are sometimes anti-quantum, but not always. This is because quantum computing can quickly solve complex math problems, which can break encryption. But what makes a math problem complex? In the context of cryptographic encryption, it is a complex problem if a computer cannot analytically solve a problem faster than it takes to brute force or “guess” the answer.

The mathematical relationship between a public and private key is so complex that classical computers aren’t able to brute force or analytically find the solution within a reasonable amount of time. (For reference, it would take a classical computer approximately 300 trillion years) But quantum computers can analytically solve some of those, including Bitcoin’s.

If a user has a Metamask wallet, they have a private key that they are told to keep secret, but more often, we don’t even know why. The reason why is that no one can retrieve your private key with just your public key. It is impossible because of the complex math problems described above.

But let’s say Bob, a quantum engineer and total meatbag, wants to use the quantum computer to recover a secret key using a user’s public key. Assuming he has access to a quantum algorithm able to reconstitute private keys (such as Shor’s algorithm), all he has to do is locate the public key of a whale and finish solving the complex math problem. It might take the computer 10–20 years, but eventually, he could solve the problem and transfer the crypto. The worst part is no one will know Bob is attacking them. So what is being done to stop this?

The U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) is currently choosing the first group of post-quantum computing (PQC) algorithm tools that are designed to withstand the assault. In July, they had narrowed the standards down to four in the final round.

T.Y said currently, all four of the selected encryption algorithms (CRYSTALS-KYBER, CRYSTALS-Dilithium, FALCON, and SPHINCS) are extremely useful. The world’s best cryptographers have been working to develop them since 2016.

However, there is still a threat until the standard is agreed upon and finalized. And the problem is Bob. If Bob is already running a quantum attack, he is unlikely to write an academic paper discussing how he accomplished it. The meatbag that he is, he’s going to take the money.

So how will we avoid this, and what will it look like when a standard is adopted? T.Y said that with Ethereum and crypto stored in active addresses, Ethereum will likely be able to push an upgrade with a PQC algorithm. They will publish the news, and holders will transfer to an anti-quantum address.

The most dangerous thing is not the active accounts but the inactive ones. Big whales that, asleep for years, can’t move their crypto. Some users may have millions of Bitcoin but have lost their private key and can’t move their assets. They are unprotected from a quantum attack, which could potentially plummet the entire market if someone gains access. So how do we avoid this problem?

There are some ideas. When a standard is adopted, Bitcoin officials will announce that whales with access to their crypto should transfer to a new encryption system to avoid being quantum-vulnerable. These discussions are ongoing because this is not a gentle way of upgrading, and some Bitcoin will be lost in the process.

To sum it up:

We need to be aware of quantum attacks; we don’t know if or when they might happen. If successful, a quantum attack could disrupt the entire system. But one PQC encryption algorithm will eventually win out at NIST, and the ability to resist quantum hacking of crypto will improve dramatically.