The Impact of Quantum Computing on Cryptography

Quantum computing is the latest development that has gained a lot of interest recently. It promises speed and efficiency in performing complex calculations that no conventional systems can match, raising many possibilities in various industries. However, the most pertinent question revolves around this new technology's impact on cryptography—the technology used to protect our digital assets. Currently, the pieces of silver code we depend upon may become unprotected soon, which presents a significant danger to data integrity.

In this blog post, we will examine quantum computing's effects on cryptographic systems, the vulnerabilities it creates, and what researchers are doing to protect the next generation of cryptographic systems.

Cryptography is the foundation of information security and various secure communications. That’s how Credit card numbers, passwords, and sensitive information remain hidden from hackers. Many of today’s cryptographic systems employ complicated mathematical formulas to develop protected vital encryption. The issue is that these keys depend on particular mathematical issues that are very challenging for traditional computers to solve – but not for quantum computers. Quantum computers employ qubits unlike others, which employ bits ‘’1s and 0s’’. These qubits can be in several states at once due to superposition. This ability to exist in more than one state at a time makes quantum computers work much faster, solve algorithms, and deal with large databases faster than other computers. This means that while at it, quantum computers could solve encryption problems that would take conventional computers centuries in seconds.

This section looks at two forms of cryptography: asymmetric (public key or two-key) and Symmetric (single-key or shared secret).

Among numerous quantum computation threats, perhaps the one that would bring the most significant change is Shor's Algorithm. This algorithm applies number theory to finding prime factors of large numbers much quicker than any classical computer would. This is a serious problem for any public key cryptosystem whose security relies on the integer factoring problem, such as RSA.

This means that as soon as quantum computers are ready and have enough power, recovering any information previously protected with the RSA method would be easy, even if the private key is unavailable. This is a worrying prospect for the future of data security as almost everything now is based on the internet, from online cash transactions to sending secure e-mail messages.

Similarly, other asymmetric encryption techniques, including Diffie-Hellman and Elliptic Curve Cryptography, include methods applicable to quantum computing because their security approaches do not deter such technologies. These two comparatively modern approaches aim at solving problems that seem increasingly abstract. Still, quantum computers could potentially do this within the time limit of one minute or one hour.

Although symmetric encryption like AES is supposedly much safer in quantum attacks, it is not completely waterproof. Grover’s Algorithm can reduce the time of breaking symmetric encryption by half of the traditional method. For instance, AES-256, regarded as highly powerful and invulnerable today, may be conveniently translated to the standard of AES-128 in the quantum realm. That, of course, does not mean that symmetric encryption will become useless. Still, it will imply that the encryption standards will have to become different in certain ways. For instance, to provide equal protection, encryption algorithms could require more extensive keys to counteract quantum risks.

With rising concerns about quantum computing, experts are developing ways to counter quantum threats. Such work is called post-quantum cryptography, a study that seeks to build a code that is understandable only if there are no smarter devices’ possibilities like those of quantum computers.

Here are a few promising approaches:
Lattice-Based Cryptography: Known as lattices, this approach is highly resistant to quantum computers that are used to breach a system. Lattice-based encryption is often viewed as one of the leading contenders for post-quantum cryptography because it poses a challenge that is ill-suited to quantum computers.
Quantum Key Distribution (QKD): QKD does not use mathematical algorithms. It doesn’t use classical physics principles for communication security but employs quantum mechanics principles. If a hacker attempts to spy on the quantum key, the system can sense it because the state's quantum flips when measured. For example, QKD is theoretically perfect since it cannot be cracked—although the idea is still experimental and has not been implemented worldwide.
Code-Based Cryptography: Coded systems use error-correcting codes to protect data. An example is the McEliece algorithm, which has existed since the late 1970s. This method is generally deemed to be highly secure, but using it is not without some difficulties; the key size needed for the method is relatively big.
Multivariate Cryptography: This method is based on solving systems of multivariate equations as difficult as possible. It is one of the regions currently being studied for post-quantum cryptography because it offers problems that are hard to solve for classical and quantum computers.
Isogeny-Based Cryptography: Like elliptic curve cryptography, isogeny-based cryptography utilizes maps between elliptic curves. However, the computations involved are much more complicated, which makes it harder to beat with quantum attacks.

In 2016, the National Institute of Standards and Technology initiated an initiative to build and define quantum-resistant cryptographic algorithms from the root. In 2022, they picked out four possible candidates that could be used to derive future encryption standards.

These algorithms undergo thorough evaluation and testing, and their performance is increasing so that they will provide encoding that will be useful even in an era of universal quantum computers. While we are still several years from fully adopting quantum computing, today's activities will be gearing up for the real cryptographic protection that the future will face.

The influence of quantum computers on the art of cryptography is quite huge. Almost every system based on encryption, such as secure Internet transaction systems and military communication systems, is in danger.

Financial Services: Banks and other financial institutions use encryption when providing money transactions and confidential information services. If quantum technology can break these systems, financial forgery, identity theft, and customer data breaches are bound to occur.
Healthcare: Most health records and other sensitive patient information are encrypted while stored or transmitted. This means that this information is very private and sensitive. A quantum attack could access this information, leading to a violation of privacy or, if medical records are altered, fatal accidents caused by hard-to-treat diseases.
Government and Military: For obvious reasons, the government needs encrypted communication to function adequately due to national security stakes. The threat of being able to decrypt sensitive information is critical from the point of view of national security, and it can compromise classified information.

Even though quantum computers capable of breaking encryption systems are still years away, the time to start preparing is now. Organizations should take several key steps:
Audit Cryptographic Systems: Determine where in your organization encryption takes place and assess the system's data lifetimes. Information to be retained for fifty years must be provided with quantum-safe solutions.
Adopt Hybrid Systems: For now, one could use a combination of classical cryptosystems and quantum-resistant ones to provide an additional shield. This way, unlike implementing a single security system, another safer one may still be compromised.
Stay Informed: Track NIST’s current developments of post-quantum cryptography standards and be ready to start using quantum-resistant cryptography once they are released.
Collaborate with Security Experts: Engage with your cybersecurity teams to help your organization prepare for what happens after quantum computers hit the mainstream. This may include enhancing hardware, software, and protocol to implement quantum-resistant cryptographic solutions.

Quantum computing has great potential and presents a great danger to digital security. Although it may take years for quantum computers to be used commonly, the call to action is now. The collaboration of cryptographers, researchers, and organizations is paramount to ensure that encryption systems are in place that cannot be broken by quantum computer capabilities. Today, we can prepare ourselves and embrace cryptography, which even the most advanced quantum computers cannot compromise, to ensure that tomorrow’s security and sensitive information will be well guarded.