Quantum Secure Group Communication

Zheng-Hong Li, M. Suhail Zubairy, M. Al-Amri
2018 Scientific Reports  
We propose a quantum secure group communication protocol for the purpose of sharing the same message among multiple authorized users. Our protocol can remove the need for key management that is needed for the quantum network built on quantum key distribution. Comparing with the secure quantum network based on BB84, we show our protocol is more efficient and securer. Particularly, in the security analysis, we introduce a new way of attack, i.e., the counterfactual quantum attack, which can steal
more » ... information by "invisible" photons. This invisible photon can reveal a single-photon detector in the photon path without triggering the detector. Moreover, the photon can identify phase operations applied to itself, thereby stealing information. To defeat this counterfactual quantum attack, we propose a quantum multi-user authorization system. It allows us to precisely control the communication time so that the attack can not be completed in time. An arbitrary unknown quantum state can not be cloned. The statement known as quantum no-cloning theorem 1 indicates a robust way to secure communication. Based on this, the first quantum key distribution protocol (QKD), BB84 2,3 , is published in 1984. It allows two communicators to generate a unique key to encrypt messages. After that, during three decades of intense research, a mass of quantum secure communication protocols have been designed and published. They include not only QKD protocols 4,5 , but also direct secure quantum communication protocols 6-8 , quantum public-key cryptography 9-12 and so on 13-17 . In addition, aimed at practical application, techniques such as decoy states 14,18-20 , device independent QKD 21-24 are also studied. No doubt, to achieve a quantum secure network is one of the most important goals of all of the above studies 25 , where QKD is the most promising protocol for application. However, considering network environment, QKD has disadvantages. For security reasons, the distributed key in QKD is disposable, which is called one time pad. This brings in the key management problem when more than two communicators are involved 9 . Since all keys are used once and discarded, it is meaningless to share them among communicators for further use. When the number of communicators increases, a mass of keys need to be managed, which takes lots of resources 9 . A solution to the key management problem in quantum secure network is quantum public-key cryptography 9-12 , which utilizes quantum one-way function 26, 27 . Generally speaking, there is a public key that is only capable of encoding message, while there is another private key, which is just for decoding message. As a result, a receiver who holds the private key can collect information from a large number of senders. Thus, unidirectional group to point communication is achieved. In addition to quantum public-key cryptography, there are multi-party quantum cryptography protocols 28-32 based on multi-party entanglement states. Those protocols require particles held by different communicators are entangled before the communication. Then, after the communicators perform appropriate measurements (disentanglement process) and negotiate with each other, a shared key can be determined. In this paper, however, we solve the key management problem by another way. Without utilizing multi-party entanglement states, we create and share a key among more than two users, so that all authorized communicators can use the shared key to encode and decode information. More specifically, this shared key is pre-selected by Bob himself (the key initiator). The key generation process is irrelevant to other communicators (participants) and can be achieved by a quantum random number generator 33 . After that, the key is sent directly and independently to other communicators. Our protocol is based on the Ping-Pong protocol 6 , which is one kind of direct secure quantum communication protocol between two communicators. In the Ping-Pong protocol, Alice (the message Published: xx xx xxxx OPEN www.nature.com/scientificreports/ 2 ScIentIfIc RepORTS | (2018) 8:3899 |
doi:10.1038/s41598-018-21743-w pmid:29497080 pmcid:PMC5832868 fatcat:24rxxfa4w5aofmkazkythav65y