Recently, the International Telecommunication Union (ITU), one of the three major international standardization organizations, approved and released the international standard "Security Requirements for Quantum Key Distribution Node Protection." This is the first systematic international standard for the secure implementation and deployment of trusted relay nodes, providing guidance for the secure implementation and operation of quantum secure communication network nodes. The standard was led by China Quantum Communication Network Co., Ltd., in collaboration with QuantumCTek Co., Ltd., and the National University of Singapore, and received active discussion and support from experts in Japan, South Korea, and Europe.
Quantum secure communication technology based on Quantum Key Distribution (QKD) is currently the most advanced practical quantum information technology. Its security is guaranteed by the fundamental principles of quantum mechanics, enabling data transmission that is immune to eavesdropping and decryption. Due to signal loss, the current secure distance for point-to-point fiber QKD in existing networks is on the order of hundreds of kilometers. The quantum secure communication network based on trusted relays is the only widely adopted solution for long-distance fiber quantum secure communication networks. National wide-area quantum secure communication backbone networks in China, the Pan-European Quantum Secure Communication Network, and the East Coast Quantum Secure Communication Network in the United States have all extended their coverage by deploying trusted relays.
The newly released international standard clarifies the types of security threats faced by relevant nodes, proposes security requirements and specific security measures, and provides authoritative international normative guidance for the design and security evaluation of quantum secure communication networks worldwide. It is expected to promote the construction of quantum secure communication networks globally, achieving mutual promotion of standards and applications.
Unstoppable Fiber Attacks
Global network security is facing severe challenges, with network espionage methods and technologies continuously evolving, becoming increasingly covert and efficient, making them difficult to defend against. Not only are hacker attack methods highly diverse and complex, but a new method-fiber optic attacks-is also gradually being applied to network attacks.
Over the past decade, fiber optic communication has become the backbone of modern communication networks due to its high speed, large capacity, and low loss, and is widely used for data transmission between the internet, telecommunications, and data centers. However, with the exposure of optical attack technology, this communication method has revealed new vulnerabilities.
Fiber optic attacks, as the name suggests, refer to destructive or eavesdropping actions targeting fiber optic communication systems.
Few people know that if a fiber optic cable is bent at a specific angle to refract a weak light signal, and then captured and reconstructed using specialized equipment with laser technology, the desired information can be obtained, thus achieving eavesdropping on communication content.
Another method of fiber optic attack is to inject false or interfering signals into the fiber optic cable, which can alter data or cause communication errors. Hackers can even use Optical Time Domain Reflectometry (OTDR) equipment to detect the physical layout of the fiber optic network from a distance, identify network node locations, and prepare for physical destruction or precise attacks.
U.S. national security expert James Bamford once revealed that the U.S. nuclear-powered attack submarine "Jimmy Carter" has the capability to eavesdrop on undersea fiber optic cables.
Since the rapid development of laser and fiber optic technology in the 1980s, fiber optic attacks have gradually emerged. Because attack equipment can intercept and decode fiber optic signals through non-physical contact, achieving remote monitoring and data theft, it poses a serious threat to national security and the safe operation of critical infrastructure, presenting a new challenge to existing network security defense systems.
"One-Time Pad" Ensures Security
To address this threat, researchers are committed to developing encryption technology and physical layer security solutions for fiber optic communication, aiming to build stronger defense barriers at the fiber optic layer.
Quantum secure communication technology based on Quantum Key Distribution (QKD) is currently the most advanced practical quantum information technology. It is based on physical principles and is a secure key transmission method guaranteed by quantum mechanics.
One of the basic characteristics of quantum mechanics is that it cannot be observed, also known as the "Schrödinger's cat" experiment.
In simple terms, the basic principle of quantum key distribution is to transmit key information through quantum states (usually the polarization state or photon number state of photons). The sender and receiver exchange quantum states and use the properties of quantum mechanics to detect the presence of eavesdropping. If a third party attempts to obtain information, both parties will immediately detect it and discard that part of the key. Ultimately, both parties share an absolutely secure key for encrypting and decrypting subsequent communication content.
On the other hand, traditional cryptography is usually based on a specific rule. Once an attacker obtains the rule or uses brute force to crack it, especially with the potential scientific leap of quantum computing, the current cryptographic system will be defenseless. Quantum key generation, however, utilizes the randomness of quantum mechanics, which is completely ruleless and physically generated, making it highly unpredictable.
An unpredictable key pair, an unobservable state, and a "one-time pad" security mechanism achieve data transmission that is immune to eavesdropping and decryption.
