Cryptocurrency gets its name from “cryptography”, which quantum computers could crack, threatening not just crypto, but the entire internet.
With the rise of quantum computers, one of the biggest concerns in the world block chain is their purported ability to crack cryptographic encryption algorithms, allowing them to tear apart the security that blockchains were designed to provide. Much of the internet is built on cryptographic algorithms that even the world’s fastest supercomputers can’t crack (quickly), but a powerful enough quantum computer could crack everything in moments. Because quantum computers could one day crack the cryptography that protects crypto wallets, they are seen as an imminent existential threat.
Cryptocurrency takes its name from cryptography, a field of mathematics dedicated to encrypting and decrypting messages. Thanks to cryptography, e-commerce websites, social media, banking applications, and virtually any exchange of sensitive data can exist without the threat of hackers intercepting the data. Bitcoin was the first blockchain in existence, a computer network that uses cryptography and cryptocurrency mining to store data on a public ledger that cannot be censored or altered. Blockchains, especially Bitcoin, use the SHA-256 hashing algorithm to produce unique, fixed-length “fingerprints” for each block of data that links it to all previous blocks of data in the chain. This algorithm is impossible to reverse for digital computers and that is why crypto mining is so energy intensive.
As CoinTelegraph explains, quantum computers could (theoretically) break through the SHA-256 hashing algorithm that Bitcoin and many other blockchains rely on to produce blocks and sign transactions. If this happened, a quantum computer could forge transaction signatures, recover private keys from public keys, alter data in the blockchain’s history, overtake all miners/validators on the network, and completely hijack the blockchain. Given that the decentralized finance (DeFi) sector holds several billion dollars in value (as of 2022), there is a huge economic payoff for anyone who can crack blockchain crypto.
Although this is a likely threat, it’s time to prepare
This is not a good thing for blockchain technology. While some blockchains were designed to be “quantum resilient” and will survive the rise of quantum computing in their current form, other blockchains like Bitcoin and Ethereum are not equipped to deal with an attack from a hacker. quantum computer. Additionally, this attack would destroy the security of Ethereum’s decentralized applications (dApps) as well as all Internet applications that rely on AES and SHA-256 encryption, on which most of the Internet is built.
Fortunately, a quantum computer would need millions of “qubits” to crack modern cryptography, but currently they have less than 100 qubits. So while quantum computers can do amazing things like simulate physics inside a black hole, they can’t yet reverse a cryptographic hashing algorithm, and won’t be able to for a while. Additionally, blockchains can be upgraded as long as all miners/validators running the network agree to implement the upgrade. While blockchain upgrades are extremely rare due to disagreements with independent miners/validators, quantum resistance will be a matter of life and death for blockchain technology. There is no rational excuse for a miner/validator to refuse a quantum resistance upgrade when the threat of a quantum attack becomes plausible.
While quantum computers threaten blockchains, this threat will not become a reality for at least a few decades (barring major technological advances). Bitcoin’s creator(s), Satoshi Nakamoto, did not anticipate the rise of quantum computing, but provided Bitcoin with the ability to upgrade. There is still time for mathematicians to discover better forms of quantum resistant cryptography and to block chain miners/validators to implement it.