Quantum Computing: Federal Actions Needed to Prepare for Emerging Cyber Threat

What GAO Found 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 gain access to sensitive information; and decrypt (or unlock and view) data that the actor acquires and stores prior t...