A recent study by Google has revealed that quantum computers may be capable of breaking current encryption methods much sooner than previously estimated, raising alarm bells across the cybersecurity and cryptocurrency communities.
Back in 2019, Google researchers projected that it would take 20 million qubits for a quantum computer to crack RSA-2048 encryption—an algorithm used to protect everything from WhatsApp messages to Bitcoin transactions. However, their new findings, published on May 21, 2025, drastically revise that estimate. According to researchers Craig Gidney and Sophie Schmieg, the same encryption could now theoretically be broken by a machine with just one million qubits operating for a week—a 20x drop in qubit requirements.
This shift reflects significant advancements in quantum algorithms and error correction techniques, which reduce the number of qubits needed to perform complex computations reliably.
Though current quantum systems only possess between 100 and 1,000 qubits, the research underscores a rapidly approaching need for post-quantum cryptographic (PQC) solutions. If an adversary were to harvest encrypted data today, they could decrypt it in the future once quantum technology matures—a tactic known as “store now, decrypt later.”
Google stressed the urgency of transitioning away from RSA and other asymmetric encryption methods, especially in contexts like financial transactions and secure communications. Cryptocurrencies are especially at risk due to their reliance on public-private key cryptography like Elliptic Curve Diffie-Hellman, which quantum algorithms such as Shor’s Algorithm can break with ease.
Efforts are already underway to tackle this looming threat. Google is working with the US National Institute of Standards and Technology (NIST) and other stakeholders to promote the adoption of new encryption standards. NIST’s recent PQC competition has produced algorithms that can now be deployed preemptively, well before quantum computers reach cryptographic relevance.
While the construction of a million-qubit machine remains a significant technical hurdle, this study serves as a wake-up call: the quantum future is closer than we think—and it’s time to prepare.
