Traditional computing models are actually “pre-modern” in that the model of physics they take as their starting point is “classical.” They rely on formulae more analogous to Newton’s laws of motion than the quantization paradigm. But quantum computers are the order of the day, and they are about to take over the world. Recently, Google used its state-of-the-art quantum computer to complete a complex computational problem in 200 seconds. That’s over three minutes, so before you act unimpressed, it was a problem that would have taken 10,000 years for any non-quantum supercomputer to finish. So okay then.
The prospect of a computer operating 1.5 trillion times faster than its classical predecessors raises a number of questions, one of which is the effect such a quantum leap will have on issues surrounding cryptocurrency. As they are currently manifesting, cryptocurrencies are too unstable to be economically advantageous. They constantly fluctuate in price. Imagine having a hundred dollars in your pocket, but not knowing whether the lunch you buy tomorrow will cost $15 or $75. You would quickly opt out of that monetary system if you could.
Well, add to those troubles a new one brought to you by quantum computing: the ability to break open blockchain. Blockchain refers to the electronic “ledger” of transactions for cryptocurrencies like Bitcoin. That ledger is encrypted and thus the privacy of transactions is preserved, fulfilling cryptocurrency’s original promise to operate independently of governments and central banks.
But “blockchain transactions are secured with digital signatures based on elliptic curve cryptography (ECC).” And ECC can be broken by quantum computing; this is an oversimplification, but imagine a computer fast enough to go through millions of potential codes in just a few seconds. A quantum computer could thus decrypt users’ private keys and even forge transactions attributed to those users. If cryptocurrency is mostly based on trust, that spells the end of such trust.
Perhaps, following Jack Matier, the answer lies in instilling quantum security in blockchain. “[A]t some point,” Jack writes, “blockchain developers will need to update the cryptographic portion of their blockchain to be quantum-resistant.” Jack says signature schemes can be upgraded to become “crypto-agile.” And once blockchain schemes are developed with that agility, the total population of users will have to “manually migrate” to the new platform, or else people will find their funds locked up or left defenseless against hacking.
Cryptocurrency came into the world with a lot of promise. It was supposed to give users autonomy and efficiency. It had (and still has) the potential to lift people out of poverty by giving them control of their finances (without stiff banking fees) and making international financial transactions, including remittances, easier. It even has the potential to help autonomous national movements achieve financial independence from their colonizers. The question is whether anything can remain “crypto” in a world of unbelievable and breathtakingly fast quantum computing.