The transition to post-quantum cryptography is anticipated to be a significant challenge. Experts from a leading cybersecurity center in Germany, Athene, assert that various steps can be taken in the immediate term to prepare for a future where classical encryption methods are inadequate for protecting sensitive information.

In late May, the National Research Center for Applied Cybersecurity, known as Athene, unveiled a comprehensive operational guide for post-quantum computing, made possible through funding from the Hessen authorities, the region that encompasses Frankfurt, Germany’s financial center. The guide aims to assist local authorities in Hessen and, as co-author Leonie Wolf explains, is adaptable for organizations of varying sizes. “The range is substantial, covering everything from small towns with limited IT staff to larger urban centers,” she noted.

Currently, classical asymmetric encryption mechanisms, including Diffie-Hellman key exchange and RSA, serve securely to safeguard data. However, the rise of quantum computing poses a significant threat; it may allow malicious actors to employ methods, such as Shor’s algorithm, to breach these established cryptographic frameworks, raising alarms among cybersecurity experts.

Despite quantum computers still being largely experimental, with issues such as high error rates hindering their commercial viability, the indirect implications of their future capabilities are pressing. “Even if quantum computers don’t fully materialize for another ten years, information exchanged today is already vulnerable,” Wolf cautioned.

Recognizing the urgency of this matter, European authorities are actively mapping out strategies for the transition to post-quantum technologies. A year ago, the European Union released a detailed road map aiming for a transition deadline of 2035, while Germany adheres to this timeline. In contrast, French ministries have been directed to implement post-quantum cryptography for sensitive data by the end of 2030, highlighting a varied approach across the continent.

Wolf and her colleagues at Athene developed the newly published operational guidance with input from various Hessian local authorities. According to her, the urgency, particularly stemming from the “harvest-now-decrypt-later” scenario coupled with an uptick in cyberthreat incidents, has made this transition a compelling topic. “Interest has surged; our invitation to workshops attracted a considerable number of participants,” Wolf observed, indicating a notable demand for information in this arena.

However, it is essential for organizations to initiate this transition with “no-regret moves.” This approach not only enhances existing IT security but also facilitates a future shift towards post-quantum computing. Initial steps should include understanding the stakeholders affected, garnering their support, and compiling a detailed inventory of the current IT framework—covering systems, applications, external dependencies, communication protocols, software libraries, and cryptographic algorithms.

“It’s vital to have this comprehensive overview as you tackle your cryptographic needs and overall IT security,” Wolf emphasized. Yet, she noted that many local authorities and organizations struggle to complete even this crucial first phase, underscoring the considerable scope of the undertaking.

As security demands evolve, the need to balance urgency with the length of time data needs to remain secure becomes increasingly crucial. “If data needs to be secure for 20 to 30 years, you may already be too late in your preparations. However, a five-year timeline offers a bit more flexibility,” Wolf explained.

Athene’s risk analysis guidance employs a scoring system aligned with the EU road map, weighing factors such as the vulnerability of existing encryption protocols, potential damages from compromised data, and the expected migration challenges. This analysis is enhanced by supplementary insights drawn from a 2024 audit by Dutch authorities, ensuring a well-rounded approach to transitioning to post-quantum standards.

When assessing vulnerabilities, Athene’s guidelines emphasize evaluating the combinations of algorithms used and their collaborative effectiveness. For example, if algorithms operate in a hybrid configuration, the safety of the most robust component will dictate overall security. Conversely, in parallel configurations, the system may falter at its weakest link.

A significant concern for public sector bodies—and indeed many companies—is the specialized applications that were created for their unique needs, which “cannot easily or quickly be updated to post-quantum standards,” as highlighted in Athene’s guidance document. Nevertheless, organizations can still undertake measures to move towards migration, particularly if they incorporate standard components that can accommodate quantum-resistant or hybrid methodologies.

Athene particularly highlights the urgency of addressing the “harvest-now-decrypt-later” issue by prioritizing secure transmission pathways. Options to enhance current practices exist; for example, OpenVPN now incorporates quantum-resistant implementations, and the 1.3 version of the Transport Layer Security protocol aligns with post-quantum directives. Similarly, contemporary iterations of the OpenSSH remote administration tool are designed with quantum resilience in mind.

“Our recommendation is to initiate in areas identified as high-risk through your analysis, where you can also implement straightforward changes, such as adopting TLS where applicable,” Wolf advised.

For applications that seem unlikely to integrate post-quantum computing support in the immediate future, Athene’s guidance suggests operating these applications behind a reverse proxy or utilizing a quantum-resistant VPN connection, thereby ensuring layered security until a more comprehensive update can be achieved.

Ultimately, the need to replace unsupported applications will emerge, paving the way for new procurement strategies. Athene’s guidance articulates the documentary requirements that vendors must fulfill to ensure transparency, advocating for at least one quantum-resistant key exchange method and, particularly for sensitive systems, one quantum-resistant signature algorithm. The salience of these recommendations has been reinforced by earlier technical guidelines released by the German Federal Office for Information Security earlier this year.

This journey towards robust cryptographic evolution is extensive and necessitates prompt action, particularly considering the stringent regulations that govern Germany’s public sector. “Given the strict tendering regulations local authorities must follow, they require significant time to define their needs and criteria,” noted Wolf. “With these tenders often bound for years, the urgency of this issue cannot be overstated.”