As a reminder, current estimates are that quantum cracking of a single 2048-bit RSA key would require a computer with 20 million qubits running in superposition for about eight hours. For context, quantum computers maxed out at 433 qubits in 2022 and 1,000 qubits last year. (A qubit is a basic unit of quantum computing, analogous to the binary bit in classical computing. Comparisons between qubits in true quantum systems and quantum annealers aren’t uniform.) So even when quantum computing matures sufficiently to break vulnerable algorithms, it could take decades or longer before the majority of keys are cracked.
The upshot of this latest episode is that while quantum computing will almost undoubtedly topple many of the most widely used forms of encryption used today, that calamitous event won’t happen anytime soon. It’s important that industries and researchers move swiftly to devise quantum-resistant algorithms and implement them widely. At the same time, people should take steps not to get steamrolled by the PQC hype train.
If qbits double every year, we’re at 20 million in 15 years. Changing crypto takes a very long time on some systems. If we’re at ~20000 in 5 years, we better have usable post quantum in place to start mitigations.
But I’m not convinced yet, we’ll have those numbers then. Especially error free qbits…
And then we need to increase coherence time, which is 50ms for the current 433 qubits large chip. Error correction might work, but might not
Error correction does fix that problem but at the cost of increasing the number of qubits needed by a factor of 10x to 100x or so.