World's first post-quantum secure transport system capable of switching cryptography methods without interrupting communications

News Highlights:

TOKYO - October 30, 2024 - NTT Corporation (Headquarters: Chiyoda Ward, Tokyo; Representative Member of the Board and President: Akira Shimada; hereinafter "NTT") has developed a quantum-safe secure transport system that can switch cryptography methods without interrupting communications. This system uses NTT's proprietary Elastic Key Control technology (a technology that flexibly combines multiple cryptography methods), enabling rapid, secure combination of different cryptography methods and smoother switching. This effectively protects data from current and future security threats. In addition, this system can incorporate state-of-the-art post-quantum cryptography as a cryptography method, and it complies with the new security standards set by the U.S. National Institute of Standards and Technology (NIST), effectively preventing decryption by quantum computers.
　This system will be used in the IOWN International All-Photonics Network (APN) connecting Japan and Taiwan and will be exhibited at NTT R&D FORUM 2024-IOWN INTEGRAL¹-from November 25 to 29, 2024.

Background

Cryptography is a crucial technology that forms the foundation of a highly developed digital society. However, due to the rapid evolution of computer technology and the emergence of new attack methods, it is necessary to regularly update the cryptography methods in use. Technological advancements in quantum computing render many of the currently widely used cryptographic algorithms vulnerable to decryption, making it essential to address this issue to maintain trust and security in the digital society.
　To address this challenge, NIST, a U.S. standards organization, is developing and standardizing new cryptographic algorithms that can withstand quantum computers. These new post-quantum cryptographic algorithms are expected to be widely available by 2030, and migrating to post-quantum cryptography as a matter of priority is recommended, especially for long-term data storage and critical communications. However, the transition to new cryptographic methods is technically challenging and is widely recognized as the "2030 Cryptography Problem."
　To respond to such threats, "Crypto-agility" (cryptographic flexibility) is an important concept that enables rapid updating of cryptographic methods. This refers to the ability to quickly update cryptographic methods, enabling swift response to new security threats. Many professional organizations, including NIST, emphasize the importance of this capability and recommend crypto-agility as a future security measure.

Key Achievements and Technologies

In preparation for the quantum computer era, NTT has developed the world's first post-quantum secure transport system that supports advanced crypto-agility. This enabled a rapid transition to new cryptographic method with minimal disruption to service and security risks.
　This system utilizes NTT's proprietary Elastic Key Control technology and achieves advanced security by combining multiple key exchange algorithms (Figure 1). Elastic Key Control technology operates in a two-stage configuration: 1) multiple keys are shared among devices using multiple cryptographic algorithms as a key exchange method, and 2) these keys are hybridized to generate a single common key. This structure ensures that communications remain secure unless all cryptographic algorithms in use are compromised simultaneously, providing a higher level of security than previously available technologies. Additionally, the architecture is designed to support multiple keys, allowing for smooth ciphers updates without disruption. As a result, this system can provide continuous service while maintaining communication reliability and can respond quickly and flexibly to future threats.

Figure 1 Development and Implementation of Elastic Key Control Technology

Conventional optical transport systems have been provided in an integrated form, but recent technological advances and demands have led to more open systems. However, since the cryptographic module depends on the network operating system (NOS) of the appliance, there was little flexibility in cryptographic processing. To enhance flexibility, we implemented a "disaggregation" configuration in which encryption processing is separated from NOS (Figure 2). As a result, key management, session management, and encryption processing can be controlled externally, and cryptographic functions for post-quantum cryptographic communication can be integrated and managed in open optical transponders. Table 1 shows the specifications of cryptography methods supported by the developed system.

Figure 2 Disaggregation Configuration of Developed and Implemented Cryptography

Table 1 Functions and Specifications of Quantum-Safe Secure Transport Systems

Outlook

By developing our quantum-safe secure transport system, we aim to strengthen the security of critical infrastructure such as finance, healthcare, and government, contributing to the realization of a safe and secure society. It will also enhance the security of international communications and ensure global reliability. This system will be utilized on the world's first IOWN international all-photonics network (APN) connecting Japan and Taiwan.

¹"NTT R&D FORUM 2024 -IOWN INTEGRAL" Official Website: https://www.rd.ntt/e/forum/2024/
In addition to applications such as data replication using international APNs and GPUs over APNs, it will also be demonstrated as part of IOWN PETs (IOWN Privacy Enhancing Technologies), which aim for consistent data sovereignty protection from creation to destruction.

About NTT

NTT contributes to a sustainable society through the power of innovation. We are a leading global technology company providing services to consumers and businesses as a mobile operator, infrastructure, networks, applications, and consulting provider. Our offerings include digital business consulting, managed application services, workplace and cloud solutions, data center and edge computing, all supported by our deep global industry expertise. We are over $97B in revenue and 330,000 employees, with $3.6B in annual R&D investments. Our operations span across 80+ countries and regions, allowing us to serve clients in over 190 of them. We serve over 75% of Fortune Global 100 companies, thousands of other enterprise and government clients and millions of consumers.