Digital signatures are widely used for providing security of communications. At the same time, the security of currently deployed digital signature protocols is based on unproven computational assumptions. An efficient way to ensure an unconditional (information-theoretic) security of communication is to use quantum key distribution (QKD), whose security is based on laws of quantum mechanics. In this work, we develop an unconditionally secure signature scheme that guarantees authenticity and transferability of arbitrary length messages in a QKD network. In the proposed setup, the QKD network consists of two subnetworks: (i) an internal network that includes the signer and with limitation on the number of malicious nodes and (ii) an external network that has no assumptions on the number of malicious nodes. A consequence of the absence of the trust assumption in the external subnetwork is the necessity of assistance from internal subnetwork recipients for the verification of message-signature pairs by external subnetwork recipients. We provide a comprehensive security analysis of the developed scheme, perform an optimization of the scheme parameters with respect to the secret key consumption, and demonstrate that the developed scheme is compatible with the capabilities of currently available QKD devices.
翻译:数字签名被广泛用于通信安全。与此同时,目前部署的数字签名协议的安全建立在未经证实的计算假设基础上。确保无条件(信息理论)通信安全的一个有效途径是使用量子钥匙分配(QKD),其安全以量子力学法为依据。在这项工作中,我们开发了一个无条件安全的签名计划,保证QKD网络中任意长度信息的真实性和可传输性。在拟议的设置中,QKD网络由两个子网络组成:(一) 包括签名人的内部网络,对恶意节点的数量有限制;(二) 外部网络,对恶意节点的数量没有假设。外部子网络中缺乏信任假设的一个后果是,内部子网络接收人必须协助外部子网络接收人核实信息签名配对。我们提供了对开发计划的全面安全分析,对秘密钥匙消费的系统参数进行了优化,并表明开发的计划与目前可用的QKD设备的能力相符。