Quantum Computing: Federal Actions Needed to Prepare for Emerging Cyber Threat [Reissued with revisions on Oct. 14, 2026]

Quantum computers have the potential to solve problems much faster than standard computers. But they could also break cryptography—the mathematical processes that can “lock,” “unlock,” or authenticate information—on federal systems. This could put sensitive data at risk.

Experts believe a quantum computer capable of breaking such cryptography could be developed as soon as the 2030s. To protect their data, federal agencies need to transition their systems to more secure cryptography. But they haven't gotten ready to do this, by, for example, fully identifying vulnerable systems or testing quantum-resistant algorithms.

A person holding a small electronic device with the words "Quantum computing" on it with several computer icons overlayed on the image.

Quantum computers leverage qubits (the quantum equivalent of classical computer bits) to solve specific problems significantly faster than classical computers. However, the emergence of quantum computers could undermine the cryptography (e.g., encryption) that federal agencies use to secure their systems. Today’s quantum computers cannot yet break this cryptography. But a future quantum computer of sufficient size and sophistication—referred to as a cryptographically relevant quantum computer (CRQC)—could potentially do so for certain cryptography.

Most industry experts believe that a CRQC will be developed, possibly as soon as the 2030s. However, development estimates vary widely due to several factors, such as uncertainty in the rate of growth for qubits and how many qubits will be needed. Once a CRQC is developed, its use could have devastating impacts to federal systems reliant on vulnerable cryptography. For example, a malicious actor could use a CRQC tocompromise systems that ensure the authenticity of system users—thus allowing the actor to