A researcher from the Google Quantum AI research team has estimated that a quantum computer with less than a million noisy qubits could undermine the security of RSA-2048 encryption that secures everything from web communications to financial transactions.
In a research paper, quantum software engineer Craig Gidney said: “I estimate that a 2048 bit RSA integer could be factored in less than a week by a quantum computer with less than a million noisy qubits.”
The research paper demonstrates the need to move beyond RSA-2048 quickly as quantum computing become more powerful.
While a million qubit system may seem a long way off, the fact that RSA-2028 encrypted data can be cracked in a week means that once such systems are available, hackers would be able to decrypt stolen data, potentially revealing bank card and other personally identifiable information far quicker.
There are industry-wide efforts underway to migrate away from RSA-2048 to quantum-safe encryption.
The US National Institute of Standards and Technology has ratified a number of post-quantum cryptography (PQC) standards. Financial institutions face pressure from regulators to replace RSA-2048 encryption by 2035 and migrate fully over to quantum safe encryption standards to protect banking transactions.
Quantum evolution
Today’s quantum computers are generally noisy. This intermediate stage in the evolution of quantum computing, known as Noisy Intermediate Scale Quantum (NISQ) is where the industry is currently at: noisy devices comprising a hundred or so physical qubits, but without error correction.
But with every development in quantum computing, the ability to break widely used cryptography standards such as RSA-2048 inches closer, which means every application that uses cryptography will need to be updated to use a PQC standard.
Earlier this year, Microsoft unveiled a new approach and a device Marjorie-1, which promises a way forward towards truly scalable quantum computing, where the error rate does not increase as the number of qubits increases. Microsoft describes Majorana 1as the world’s first Quantum Processing Unit (QPU) powered by a topological core, designed to scale to a million qubits on a single chip.
Discussing Gidney’s research, Michael Murphy, deputy CTO of quantum secure encryption company, Arqit, said: “It’s not just about hardware when it comes to improving quantum computing. Advances in algorithms also have a huge impact – in this case, we got a 20x speedup. It emphasises again that there’s no equivalent to Moore’s law for quantum computing; advances will come in large steps that are unpredictable.”
“Instead of guessing when we might reach ‘Q-day’, it’s far better to take a risk-based approach and start your migration to quantum-safe security as soon as possible,” Murphy added.
