EncryptionNew cryptography must be developed and deployed now, even if quantum threats are a decade away

Published 5 December 2018

Given the current state of quantum computing and the significant challenges that still need to be overcome, it is highly unlikely that a quantum computer that can compromise public-key cryptography – a basis for the security of most of today’s computers and networks – will be built within the next decade, says a new report by the National Academies of Sciences. However, because replacing an established internet protocol generally takes over a decade, work to develop and deploy algorithms that are resilient against an attack by a quantum computer is critical now.

Given the current state of quantum computing and the significant challenges that still need to be overcome, it is highly unlikely that a quantum computer that can compromise public-key cryptography – a basis for the security of most of today’s computers and networks – will be built within the next decade, says a new report by the National Academies of Sciences, Engineering, and Medicine. However, because replacing an established internet protocol generally takes over a decade, work to develop and deploy algorithms that are resilient against an attack by a quantum computer is critical now.

NAS says that the committee that conducted the study and wrote the report was charged to explore the area of quantum computing and bring clarity about the current state of the art, likely progress toward a general-purpose quantum computer, and the ramifications of its development.

While defeating currently deployed public-key encryption using the best available conventional computer is effectively impossible, a quantum computer could potentially perform this task in no more than a few hours. Even if a sufficiently advanced quantum computer does not arrive within the next thirty years, the report emphasized the need to begin transitioning to quantum resilient procedures to prepare for an attack by such a system, as it takes over a decade to replace existing web standards.

The report describes how a quantum computer operates, describing both the advantages and constraints of this type of computing. It points out that quantum computers cannot improve all computing and require today’s computing technologies to operate, so quantum computers are unlikely to replace current computers. Rather, they are more likely to be used as accelerators attached to more conventional computers.

A quantum computer utilizes the unusual characteristics of quantum mechanics –the nonintuitive behavior of very small particles – to perform computation, unlike current computers.  At any given point, a quantum computer, which encodes information as quantum bits or qubits, can span all possible states of a comparable classical computer. This great ability to be in many places at the same time comes with a number of constraints: the qubits need to be intrinsically interconnected, or entangled, isolated from the outside environment, very precisely controlled, and not measured.  These constraints limit the type of tasks a quantum computer can accelerate, and even these cases require careful quantum algorithm design.