TrendRobust hierarchical metropolitan quantum cryptography network
The security of a majority of classical cryptography is based on the complexity of the cipher algorithms and the development of distributed computing and specific hacking chips; this may no longer be sufficient, as quantum computing has become a serious threat to classical cryptography; the solution: quantum encryption
Practical quantum encryption Key Laboratory of Quantum Information (CAS) at the University of Science and Technology of China has recently demonstrated a metropolitan Quantum Cryptography Network (QCN) for government administration in Wuhu, China.
Information security has become more and more important for both organizations and individuals, and secure communication is a basic requirement for government, business, and personal exchanges. The security of a majority of classical cryptography, however, is based on the complexity of the cipher algorithms and the development of distributed computing and specific hacking chips.
This may no longer be sufficient, as quantum computing has become a serious threat to classical cryptography. Chinese researchers say that a brand new generation of quantum cryptography is now required for secure communication.
Quantum cryptography can distribute secret keys by encrypting the information in a quantum system, such as photons. It is founded on the principles of fundamental physics rather than assumptions about the resources available to a potential adversary, and, the researchers argue, is thus secure against any attack by eavesdroppers allowed by quantum mechanics. Combined with the quantum key distribution (QKD) and the "one-time pad" algorithm, quantum cryptography can establish unconditional secure communication between legal users, for now and the future.
Moreover, in the process of QKD industrialization, networking is a milestone for the popularization of quantum cryptography service, especially a robust QCN compatible with the classical optical network which is a potential solution for the fast growing number of users and for unforeseen emergent demands of communication.
Aiming at that, the Key Laboratory of Quantum Information (KLQI) built this brand-new quantum cryptography network. Compared with the prior network projects, Wuhu QCN implements hierarchical structure with multi-levels and contains three different existing networking techniques. Nodes with different priorities and demands are set in the central backbone net or the subnet, and choose suitable networking technique. All the QKD links are based on the BB84 protocol with decoy state method which can promise the security level for the communication. Meanwhile, QKD software that all nodes run, application programs for encrypting text messages, sound and video are developed as well.
As the authors said in the paper, "In the process of QKD industrialization, the stability of the QKD system and the networking techniques are two heavy cruxes." The Wuhu QCN implements the Faraday-Michelson Interferometer (FMI) system, an unidirectional QKD scheme with the strict proof of its security and stability which can auto-compensate the influence of the birefringence in the transmitting channel that will jeopardize the performance