Quantum Computers May Spell Doom For Cryptocurrency; Will We Be Able To Buy GPUs Again?
Quantum computers are really, really bad at most of the things we use computers for, but they're impossibly-superior at certain, select tasks. One of those tasks happens to be breaking encryption. That's a concern for security agencies the world over, but it's also a concern for people who are heavily invested in cryptocurrencies.
As the name suggests, the existence of "crypto" is entirely based on electronic encryption. Cryptocurrencies verify legitimate claims to value using a technique known as public key cryptography. This method relies on matching hashes generated with a public key—one that everyone can see—and a private key, one that you yourself hold. This works well with a secure-enough key, because brute-forcing modern encryption standards using standard computing—even the largest supercomputers—is practically impossible.
That's not the case with a quantum computing, though. Where it would take decades or centuries to crack someone's private key using conventional systems, quantum computing has the potential to do it in an amount of time on the order of hours, minutes, or even seconds. That capability would allow the operator of such a computer to break into anyone's cryptocurrency wallet and swipe the goods, whether they be digital coins, NFTs, or similar assets.
Don't panic, though—at least, not yet. Quantum computers with this kind of processing power simply don't exist, for now. Researchers are working hard to accelerate development on this new kind of computer because they can allow rapid progress on sticky issues that traditional computers struggle with, like biotech research and materials sciences. It'll be awhile before we start seeing quantum computers with the capability to crack open cryptocurrency.
This idea also hasn't escaped the world's security researchers. After all, it's not just "crypto" that's based on encryption. Almost all internet communications are encrypted these days, and if someone had the ability to simply decode and read all of the internet communications that they could intercept, it would be a major national security threat (to say nothing of the financial implications.) Researchers at the US' National Institute of Standards and Technology (NIST) have been working hard on finding "quantum-proof" cryptography algorithms, and they're surely not the only ones.
Similarly, lots of cryptocurrency creators (and other developers of blockchain-based software) are working on quantum-resistance. As one big example, Ethereum, the second-largest type of crypto-coins, has announced that the third iteration of its software will be quantum-resistant. (Of course, we're still waiting on the second version of Ethereum, so that might be a ways off.) However, CNet quotes Peter Chapman (CEO of quantum computing vendor IonQ) in saying that alleged "post-quantum" encryption algorithms "generally need ... longer processing times." That means that these latter-day encryption methods could require even more computing hardware than current versions already do.