Quantum computing is based on two key principles of quantum mechanics: superposition and entanglement.
Superposition allows a qubit—the quantum equivalent of a bit—to exist in multiple states simultaneously, unlike traditional bits which are limited to a single state (0 or 1).
Entanglement creates connections between qubits, even at a distance, a feature absent in classical computing where bits are independent. Thanks to these properties, quantum computers have computational potential far beyond that of classical computers. This technological breakthrough could rapidly turn into a social, economic, and military threat.
Rising Concerns
The main concern for security agencies like the U.S. National Security Agency (NSA) is that a nation with sufficient quantum computing power could break the encryption algorithms currently used to secure communications, including financial transactions and sensitive military and strategic exchanges. Quantum computers have the potential to defeat these encryption methods.
Traditional encryption systems like RSA and ECC rely on the complexity of factoring large numbers into primes, a process that takes an impractical amount of time for classical computers. A quantum computer, however, could factor these numbers in a very short time.
In theory, if a sufficiently powerful and stable quantum computer were built, Shor's algorithm could break most public-key cryptographic systems currently used to secure Internet communications by factoring public keys rapidly.
On March 11, in testimony before a U.S. Senate committee, Gil Herrera, Director of Research at the NSA, stated that no country currently possesses a quantum computer that would be considered useful. He noted that many teams worldwide are innovating with various quantum technologies. While unlikely in the short term, someone could make a highly unexpected breakthrough with profound and dangerous implications for security.
In short, if such technology were to fall into the wrong hands, we could all be in serious trouble.
A True Quantum Arms Race
The race to achieve quantum supremacy to break encryption algorithms mirrors the nuclear arms race of World War II. Just as nuclear weapons provided decisive strategic advantages to the nations that held them, mastering quantum computing will offer a significant edge to whichever country develops it first.
The ability to break current encryption systems could shift the balance of power by enabling one nation to decrypt its adversaries' secure communications while protecting its own. As such, the quest for quantum dominance is a fight for strategic superiority in the fields of security and intelligence, much like the race for nuclear weapons once was.
China is determined to win the quantum race. Since launching the world's first quantum satellite, Micius, in 2016, China has positioned itself as a leader in quantum research. This satellite enabled the first long-distance quantum key distribution, paving the way for unbreakable global communications.
With massive investments, China and the United States are the primary competitors in this high-stakes race. In addition to its achievements in quantum communication, China has demonstrated significant capabilities in some areas of quantum computing.
In December 2020, the Chinese quantum computer Jiuzhang performed a calculation in 200 seconds that would have taken a classical supercomputer 2.5 billion years.
Despite these advances, China is still catching up with the U.S. in the development of general-purpose quantum computing. However, China leads in quantum communications and holds the largest number of quantum technology patents.
China’s progress could eventually allow it to break modern encryption protocols, accelerate machine learning research, and win the race for quantum dominance.
The Future of Encryption
To address this looming threat, efforts are underway to develop post-quantum cryptography—cryptographic systems secure against both quantum and classical computers. In July 2022, the National Institute of Standards and Technology (NIST) announced the first four quantum-resistant cryptographic algorithms.
Unfortunately, some of the post-quantum algorithms selected by NIST have already been broken. For instance, the SIKE algorithm, which reached the fourth round of the NIST competition, was broken using a classical computer. Additionally, the CRYSTALS-Kyber public-key encryption mechanism, recommended by NIST, has also been compromised using artificial intelligence.
However, these breaches do not necessarily mean that all post-quantum algorithms are vulnerable. NIST continues its work on standardizing quantum-resistant cryptography and plans to announce additional algorithms in the future (Cloud Security Alliance, 2023).
Harvest Now, Decrypt Later
The concept of "Harvest Now, Decrypt Later" (HN-DL) presents a major challenge for financial institutions and national security. This strategy involves collecting and storing encrypted data that is currently secure, with the intent to decrypt it later using quantum computers. For financial institutions, this means today’s secure transactions could be exposed tomorrow, jeopardizing customer data privacy and financial stability.
In terms of national security, encrypted government and military communications could be decoded, compromising sensitive and strategic information. This risk highlights the urgent need for institutions to prepare for the transition to post-quantum cryptographic systems capable of resisting future quantum computing capabilities.
It is also likely that criminal organizations are already stockpiling encrypted data they have managed to exfiltrate, anticipating future use. Given the relatively low cost of data storage, this could prove to be a worthwhile long-term investment.
In conclusion, while the prospect of quantum computing poses a serious threat to cybersecurity, it is also driving innovation in the field. Whether this threat materializes in 2 years, 10 years, or never remains uncertain. But given the strategic value of compromising secure communications, it is likely that we will only learn of such a breakthrough when it is already too late.
French version: https://www.lesaffaires.com/secteurs/techno/course-aux-ordinateurs-quantiques-enjeux-pour-la-cybersecurite-2/