Shanghai UEAC Exhibition Services Co., Ltd.
What is the behavior of an adversary to launch attacks against a communication? The good choice is to eavesdrop the communication such that the communicators cannot detect the eavesdropping. The general choice is to disrupt the communication at low cost, say, measuring the transferred quantum signals in the well-known BB84 quantum key distribution protocol. The bad choice is to disrupt it at even high cost, such as severing copper or fiber, if it is necessary. In this paper the authors remark that a quantum communication is very vulnerable to low cost attacks.