Post-Quantum Cryptography: The Future of Digital Security?

The Potential Threats Posed by Quantum Computers

Quantum computers present a serious threat to the existing infrastructure of digital security. 

It is widely accepted that, at the core of this threat, is Shor’s algorithm [2] - a quantum algorithm that can efficiently solve integer factorization (the problem behind RSA encryption) and the discrete logarithm problem (which ECC relies on). With this capability, a quantum computer could easily break the public-key cryptography that supports much of the world’s internet security.

The most immediate concern, once quantum computers become widely available, is the possibility of data being intercepted and decrypted by malicious actors. Sensitive data, including government communications, financial transactions, and medical records, could be exposed. The danger for the future is that, once quantum computers become powerful enough to break the encryption, encrypted information stored today may become vulnerable.

Another major concern is the potential for “harvesting” data today for future decryption. Even though quantum computers are not yet capable of cracking encryption, adversaries could start collecting encrypted data now with the intention of decrypting it later, when quantum computers become viable. This is often referred to as “harvest-now, decrypt-later” attacks[3].

Why is Post-Quantum Cryptography Important?

The importance of PQC lies in its potential to secure our digital future. As we move closer to a reality where quantum computers become powerful enough to threaten current encryption methods, PQC offers a solution to this impending challenge. 

By developing cryptographic algorithms that are resistant to quantum attacks, PQC ensures that our data remains secure in a world where quantum computing would (by then) be commonplace.

PQC is not about simply preparing for a future problem: it is about addressing a threat that is becoming increasingly tangible. Worldwide, governments, financial institutions, and healthcare corporations are already beginning to invest in PQC research to develop and standardize algorithms that, they hope, will head off this impending threat. 

The National Institute of Standards and Technology (NIST)[4] has already launched a project to evaluate and standardize post-quantum cryptographic algorithms, which will likely provide a blueprint for the future of digital security.

Potential Victims of Quantum Computing Threats

The potential victims of quantum computing threats are wide-ranging. Anyone who relies on encrypted data for security could be affected. Potential targets could include:

Governments: Sensitive government data, national security information, and diplomatic communications could be decrypted, potentially compromising national security.

Financial Institutions: Banks and other financial institutions (including insurance companies) rely heavily on encryption to secure transactions, protect customer data, and maintain trust. Quantum attacks could put billions of dollars at risk.

Healthcare Providers: Medical records are sensitive and often contain private health information. If compromised, this could lead to identity theft or blackmail.

Corporations/Businesses: Any enterprise that stores personal or financial information could be targeted.

As you can appreciate, any incursion into the backend systems of these types of organizations could have devastating effects!

Expected Benefits from Investing in Post-Quantum Cryptography

There are a number of reasons for organizations to invest into PQC. These reasons include...

Future-Proof Security: Investing in PQC today ensures that systems are resilient to the threats posed by quantum computing in the future. This proactive approach to security helps mitigate the risk of having to urgently upgrade or overhaul systems when quantum computers become operational.

Collaboration and Innovation: The development of PQC algorithms requires collaboration between researchers, cryptographers, and engineers from various fields. This collaboration promotes innovation, leading to the creation of new technologies and security solutions that can benefit society as a whole.

Protection of Sensitive Data: With the potential for quantum computers to break encryption, PQC offers a way to protect sensitive data, such as classified government communications, financial transactions, medical records, personal information, and intellectual property. By adopting PQC algorithms, organizations can ensure that their data remains secure, as quantum computing develops.

Economic and Competitive Advantage: As the world moves toward quantum-safe encryption, early adopters of PQC will have a competitive edge. Organizations that invest in PQC will be seen as leaders in securing their systems, which can enhance their reputation and trustworthiness. This is particularly valuable for industries that handle sensitive or confidential information, such as government, finance, and healthcare.

Possible Disadvantages of Investing in Post-Quantum Cryptography

On the other hand, there are a few negative aspects to consider regarding investing in PQC...

Uncertainty and Evolution: Quantum computing is still in its infancy and, while progress is being made, the exact timeline for the development of practical quantum computers is uncertain.  Some experts expect it to take decades before quantum computers could be capable of breaking current encryption methods. This timeline disparity causes significant uncertainty. In turn, this uncertainty raises the question of whether investing in PQC now is premature, or whether we are acting wisely by preparing for an inevitable future threat.

Complexity of Implementation: PQC algorithms are often more computationally intensive and complex than traditional cryptographic methods. Implementing PQC may require significant changes to existing systems, which could be time-consuming and resource-intensive. These technical challenges could delay the widespread adoption of PQC.

Incompatibility with Current Systems: Integrating PQC into existing infrastructures may present compatibility issues, especially with older systems or devices that were not designed with quantum-resistant algorithms in mind. Transitioning from classical to quantum-resistant cryptography will require careful planning and coordination across industries and sectors.

Over-Engineering: In the rush to develop quantum-resistant systems, there is a risk of over-engineering solutions. Some organizations may invest in PQC before the technology is fully matured, resulting in wasted resources, or the adoption of algorithms that, ultimately, prove to be unnecessary.

Viable Remedies

To mitigate the risks posed by quantum computers, it would be wise to begin transitioning to Post-Quantum Cryptography as soon as possible.  And while fully quantum-secure systems may not be practical yet, there are steps that organizations can take to start their preparations now:

Monitor Research and Developments: Stay updated on the latest developments in PQC research, as new algorithms and standards are continually being tested and refined. 

Start Planning for Transition: Organizations should begin planning their migration to quantum-resistant algorithms. This could include evaluating current encryption methods, identifying potential vulnerabilities, and developing a roadmap for future-proofing systems.

Gradual Integration: As PQC standards evolve, organizations can begin implementing hybrid systems that combine traditional cryptography with quantum-resistant algorithms. Working with experts in the field can help to ensure that any potential transition to PQC will be smooth and effective. Using a hybrid approach can help ensure that systems will remain secure during the transition period.

The Future?

Post-Quantum Cryptography looks as though it is going to be an essential part of the future of digital security. As quantum computers evolve, traditional encryption methods may no longer be enough to protect sensitive data. 

By investing in PQC, organizations can safeguard themselves against the potential threats posed by quantum computing and ensure that their digital systems will remain secure in the future. 

While the road to quantum-safe encryption is not without its challenges, the benefits far outweigh the risks. By beginning the process now, organizations can ensure a secure digital future.

===

Resources / Further Reading:

[1] https://www.cisa.gov/news-events/alerts/2022/07/05/prepare-new-cryptographic-standard-protect-against-future-quantum-based-threats Cybersecurity and Infrastructure Security Agency. July 05, 2022. Retrieved February 18, 2025.

https://csrc.nist.gov/News/2024/postquantum-cryptography-fips-approved NIST Computer Security Respource Center. August 13, 2024. Retrieved February 18, 2025.

https://www.dhs.gov/quantum Homeland Security. January 28, 2025. Retrieved February 18, 2025.

[2] Shor’s Algorithm (explained) – YouTube: https://www.youtube.com/watch?v=lvTqbM5Dq4Q 

Shor’s Algorithm: https://en.wikipedia.org/wiki/Shor%27s_algorithm 

[3] Harvest Now, Decrypt Later: https://en.wikipedia.org/wiki/Harvest_now,_decrypt_later 

[4] https://www.nist.gov/news-events/news/2024/08/nist-releases-first-3-finalized-post-quantum-encryption-standards National Institute of Standards and Technology. August 13, 2024. Retrieved February 18, 2025.