What does Google's quantum computer for Bitcoin mean?

A document publié-and deleted– A few days ago, NASA revealed that we are entering a new technological era soon: Google has reached "quantum supremacy" – it seems.

According to Financial TimesGoogle claims to have successfully built the world's most powerful quantum computer. According to Google researchers, this means that calculations that normally take more than 10,000 years to complete are a computer capable of doing so in approximately 200 seconds.

Does that mean we can say goodbye to this soft cryptography that protects the integrity of Bitcoin and other digital currencies? Probably not.

Here's why.

For starters, sources at Google says Fortune Over the weekend, NASA published the document, as it could have been published without scientific peer review. A scientific publication must be evaluated and studied by a group of experts before it is ready for publication. So, it might not even be Actually be ready.

But suppose that is the case. What you need to know about Bitcoin to understand the potential threat of quantum computing, is that its architecture relies on two algorithms: ECDSA for digital signatures and SHA-256 as a hash function. If you reuse a wallet address and make a transaction, you expose your public key.

So, yes, a quantum computer could use Shor Algorithm get your private key from your public key, as recently explained Jack Matier of Quantum Resilient Ledger in a Medium post. But do not panic for the moment.

The most optimistic scientific estimates say that even if this was possible, it will not happen during this decade (enough time for Bitcoin fork and prove it quantum).

Moreover, if we consider that Google's machine is composed of only 53 "quantum bits" (qubits), a measure of the quantum power of research paper on the topic published by Cornell University can give Bitcoin buyers some peace of mind:

"A 160-bit elliptic curve cryptographic key could be broken on a quantum computer using approximately 1000 qubits taking into account the RSA 1024 bit equivalent security module, it would take approximately 2000 qubits"(Italics added). In comparison, the meager 53 qubits of Google are still not compatible with this type of cryptography.

And again, it's even a theoretical threat assuming you reused your address, which was considered bad practice even back in the day of Satoshi.

And a SHA-256 cryptographic hash is a totally different thing. He is so powerful that according to Crypto-evangelist Andreas Antonopolulos, the amount of computing power needed to break it "is greater than the wildest speculation about what intelligence agencies might have" – ​​and that by assuming they have quantum computers .

Moreover, not only quantum computing scientists can not break down Bitcoin yet, they do not seem too interested in doing so. In fact, one of the most obvious cases of using quantum technology seems to be improve encryption and cybersecurity techniques, according to Google's own researchers.

But that does not mean there is no cause for alarm at all. Although the native encryption algorithms used by Bitcoin and other proof-of-work currencies are safe for the moment, the fact is that the pace of progress in quantum technology is increasing, which could, over time, pose a threat . "We expect that their computing power will continue to grow at a double exponential rate," Google researchers said in the document since.

Fortunately, companies and research teams are already working on new cryptography algorithms for post-quantum era. And, with that in mind, it may not be a bad idea to start thinking about a potential Bitcoin fortress in a few decades that improves its "weak" security algorithm.