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NTT technical review

Secure Optical Transport Network

Tetsuya Okuda, Koji Chida, Daisuke Shirai, Chikara Sakae, Tsunekazu Saito, Misato Nakabayashi, Kazuki Yamamura, Yuri Tanaka, Katsuyuki Natsukawa, Koichi Takasugi

Published Jan 1, 2022• 6 citations
Publisher

Abstract

The implementation of an optical transport network, especially between datacenters, has been progressing.Similar to the Internet, communications on the optical transport network are protected by public-key cryptography and symmetric-key cryptography, but there are concerns that advances in the research and development of quantum computers will pose a risk to current cryptographic systems, public-key cryptography and key exchange in particular.In response to this problem, researchers at NTT Social Informatics Laboratories and NTT Network Innovation Laboratories are engaged in the research and development of safe key-exchange schemes to counter the cryptographic risks posed by quantum computers.They are also engaged in architecture design and tests with actual equipment with the aim of applying such key-exchange schemes to the optical transport network.

DOI
10.53829/ntr202201fa6

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The implementation of an optical transport network, especially between datacenters, has been progressing.Similar to the Internet, communications on the optical transport network are protected by public-key cryptography and symmetric-key cryptography, but there are concerns that advances in the research and development of quantum computers will pose a risk to current cryptographic systems, public-key cryptography and key exchange in particular.In response to this problem, researchers at NTT Social Informatics Laboratories and NTT Network Innovation Laboratories are engaged in the research and development of safe key-exchange schemes to counter the cryptographic risks posed by quantum computers.They are also engaged in architecture design and tests with actual equipment with the aim of applying such key-exchange schemes to the optical transport network.
The emergence of quantum computing poses significant risks to conventional network security, prompting researchers to focus on developments in quantum cryptography, particularly Quantum Key Distribution (QKD).According to research, it has been found that traditional security methods, like RSA encryption, could potentially be at risk from quantum algorithms.On the other hand, quantum cryptography is a field of study that leverages the principles of quantum mechanics to improve the security of communication.One of the techniques used in quantum cryptography is Quantum Key Distribution (QKD), which makes use of the unique properties of quantum particles such as photons to securely distribute encryption keys and detect any potential eavesdropping attempts, thanks to the uncertainty principle.Nevertheless, the integration of QKD into current network infrastructures poses significant challenges due to the required technological advancements.This study offers a comprehensive analysis of the fundamental principles underlying quantum cryptography, the obstacles that arise during its implementation, and its potential prospects for protecting against the risks posed by advancements in quantum computing.Furthermore, this study delves into the potential consequences of these technological advancements across different industries and emphasizes the need to create algorithms that can withstand quantum attacks to guarantee strong data security in the age of digitalization.
Cryptography, the practice of concealing messages for private exchange, has evolved significantly to address the challenges posed by new communication methods. In today`s digital world, cryptography has become the cornerstone of cybersecurity, using advanced mathematics like number theory and computational complexity to protect digital information through algorithms. The upcoming arrival of quantum computers poses a serious threat to traditional cryptographic methods, especially those based on asymmetric key cryptography. Quantum Safe Cryptography (QSC) represents the next step in information security, designed to develop cryptographic systems that can withstand attacks from both quantum and classical computers. As quantum computing moves from theory to reality, it`s becoming clear that current cryptographic methods based on integer factorization and discrete logarithm problems are vulnerable to quantum algorithms like Shor`s algorithm. This study highlights the security risks that quantum computing poses to existing encryption methods and proposes a comprehensive approach to quantum-safe cryptography. The transition to quantum-resistant algorithms involves replacing vulnerable cryptographic systems with alternatives that can resist quantum computational attacks. Current analysis shows that while asymmetric key cryptography faces immediate vulnerability, symmetric key algorithms and hash functions remain relatively secure in the near term with appropriate adjustments. Quantum cryptography, which directly uses quantum mechanical principles, offers highly secure encryption mechanisms, notably Quantum Key Distribution (QKD). This research aims to enhance the security of digital infrastructure against quantum threats by evaluating hybrid cryptographic implementations that combine classical and quantum-resistant approaches for optimal security.
In the January 2022 issue of NTT Technical Review, we introduced the secure optical transport network for enabling secure optical transport even in the era of quantum computers.In this article, two concepts, cryptographic agility and Multi-Factor Security, which are key factors in the transition from current cryptographic techniques to quantum-resistant cryptographic techniques and need to be considered in the era of quantum computers, are explained, and our efforts to incorporate these concepts into secure optical transport networks (i.e., elastic-key-control technology and disaggregation technology for cryptographic processing) are introduced.
The development of quantum computers will provide modern cryptographic systems with a practical computing infrastructure, yet the number-theoretic assumptions these systems are built on poses an acute security risk at this juncture, especially when Shor and Grover’s algorithms are considered. In this article, we present QRC-Stack (Quantum Resilient Cryptographic Stack): A modular architecture for post quantum about cyber resilient communication in current and next generation infrastructures of the internet. QRC-Stack combines lattice-based and hash-based schemes with transport layers and key management to guarantee data integrity, confidentiality, and authenticity within classical networks as well as software-defined networks. The architecture of QRC-Stack is enhanced by incorporating hybrid key exchange models that integrate classical (e.g., ECDH) and post-quantum (PQ) cryptography; Kyber and Dilithium from NIST PQC finalists to sustain legacy interoperability while advancing resilience to future threats in quantum networked environments The newly proposed QRC-Stack model includes three interrelated parts that together improve the security and flexibility of cryptographic communication within a quantum-threat context. Starting with the key management layer for quantum-aware systems (QKML), it incorporates a session key distribution system that the quantum cryptography foe cannot breach. Furthermore, the Adaptive Cipher Suite Negotiation (ACSN) injects a more node centric, risk-adaptive model in whereby selection of a cryptographic suite from a pool of available options is done dynamically where the suit best optimizes contextual threat. In addition, Q-Protect Transport Module enables seamless alignment with pre-existing transport protocols such as TLS/IPSec and QUIC or SD-WAN tunnels with limited overhead footprint. Emulation testing on SDN testbeds and active WAN environments showed that QRC-Stack sustained enterprise-class encryption throughput while adding latency overhead less than eight percent. Moreover, this hybrid architecture gives forward secrecy and stronger resistance to quantum-enhanced man-in-the-mid solar attacks with faster key refresh rates. QRC-Stack also outperformed classical TLS 1.3 alongside other variants of Transition Post Quantum Cryptography’, claiming steadfast post-compromised security while surpassing baseline models in adaptability, resilience, and versatility making it ideal for next-generation network backbone design. This information reconfirms QRC-Stack's supurb strength as an extensible multi layered blanced framework solution for communication systems in layers form situated in scenarios involving surveillance from powerful post-quantum adversaries. It helps to control the move toward safely moving quantum national, enterprise, and IoT networks from cryptographic systems built for surveillance heavy environments with minimal changes to current infrastructure.
Dense wavelength division multiplexing optical networks transport a huge aggregate traffic exceeding Tbps per single fiber, and passive optical network technology has been extended to include the residential and enterprise network layer with fiber-to-the premises. Because this network allows for multimedia and extremely high data rates to end-users, optical communications security is important not only on the client and the node management layers, but also on the physical layer. Thus, cyber-security becomes also important in optical networks, including unbreakable cipher keys, cipher key distribution, identification of malicious actors, source authentication, physical link signature, and countermeasure strategies. In this paper we overview the security of the WDM optical network. We discuss advanced cryptographic methods that stem from quantum mechanics, known as quantum cryptography, and we identify specific vulnerabilities. We also look into the security of the next-generation optical network.