Companies and governments need to act quickly to develop a comprehensive strategy for quantum readiness, says a new report by the European Policy Center, a think tank for European Union affairs. Given the current pace of quantum computing research, a quantum computer capable of breaking modern cryptography is estimated to arrive within the nexttwo decades. That’s barely enough time for policymakers to plan and implement the technical and logistical actions necessary to be ready for a world with quantum computers, says report author Andrea G. Rodríguez.
Quantum computers could wreak havoc on digital communications by breaking public-key cryptography algorithms that are used everywhere to deliver digital messages securely. When users browse to a secure website like a bank, public key cryptography helps the user and website securely exchange a secret key for encrypting all their communications. A quantum computer could blow that all apart by exposing the secret key, allowing attackers to see all communications and potentially impersonate both the user and the website.
No one should expect a cryptographically-relevant quantum computer (CRQC) to be emptying out bank accounts when they first arrive—not because they can’t, but because a bank account isn’t a worthwhile target.
But there are still limits to the types of attacks a quantum computer that can break cryptography—also known as a cryptographically-relevant quantum computer (CRQC)—can do. Just getting your hands on one won’t immediately grant you access to all existing digital communications. Each cryptographically protected connection is unique, and a quantum computer would need all its computing resources to break one connection at a time. The process also takes time—a few hours to break public key cryptography using a quantum computer, down from trillions of years on a conventional computer.
“The average user, they have a bank account, and logging in is protected by cryptography,” said Dustin Moody, who leads efforts to develop new quantum-resistant cryptography standards at the National Institute of Standards and Technology. “But someone who has a quantum computer, that’s not where they’re going to be [targeting] until quantum computers are really cheap and inexpensive to operate. And we’re nowhere near that point.”
Targets may already be susceptible to “harvest now, decrypt later” attacks based on encrypted information being gathered currently.
In other words, no one should expect a CRQC to be emptying out bank accounts when they first arrive—not because they can’t, but because a bank account isn’t a worthwhile target. Quantum computers will be expensive to operate, and as a result, attacks by quantum computers will likely be directed at high value targets like countries or important industries. In those domains, targets may already be susceptible to “harvest now, decrypt later” attacks that collect encrypted information now for future decryption using quantum computers.
NIST’s post-quantum cryptography standardization project will publish its completed standards in 2024. Moody said that if all goes according to plan, the transition to new cryptographic standards will be mostly invisible to the average digital communications user. Only organizations that use cryptography in their own code, the report says, would need to locate the places where the existing standards are used and replace it with the new ones.
Finding all the places where cryptography is used in a codebase, however, is not a trivial task. Bill Newhouse leads the project at NIST that’s in charge of the migration to post-quantum cryptography—the difficult task of actually getting organizations to adopt the new standards. He says his team is currently working with industry partners to develop tools that will help organizations locate all the points in their workflow where quantum-vulnerable cryptography is used.
“For this project, we’re trying to figure out what organizations—whether it’s government or industry—can do to begin to prepare themselves,” Newhouse says. “The concept is, you need to have an inventory of what cryptographic algorithms you rely on today, to hopefully get some notion of which ones are deemed quantum vulnerable based on their use of public-key encryption.” Once that’s determined, the true scope of the work involved to transition to new standards will be better known.
That’s why it’s important for the EU to take action and create a plan immediately, says Rodríguez, author of the EPC report. The EU has spent comparatively less time than the US developing technical solutions for post-quantum cryptography. Although European researchers have devoted substantial resources toward developing a form of quantum-based cryptography called quantum key distribution, that isn’t very mature yet, the report said. It encourages the EU to allocate more resources to post-quantum cryptography and also to testing quantum key distribution. But even when new quantum-resistant technologies are ready, migrating users over to them can take years, Rodríguez said.
Individual EU member states have started picking up the slack. A few countries have made plans for countering future quantum cybersecurity threats or have enacted strategies for doing so. But the report warns that this can create “asymmetries” between countries. That can turn into a security flaw, because an attack on any member of the EU affects the others as well, the report said. Instead, it said, the EU should act quickly and cohesively to implement plans for a quantum future.
“As we noticed, we are already late,” Rodríguez says.