Resource Allocation in Optical Networks Secured by Quantum Key Distribution
IEEE Communications Magazine
Optical-network security is attracting increasing research attention, as loss of confidentiality of data transferred through an optical network could impact a huge number of users and services. Data encryption is an effective way to enhance optical network security. In particular, quantum key distribution (QKD) is being investigated as a secure mechanism to provide keys for data encryption at the end-points of an optical network. In a QKD-enabled optical network, apart from traditional data
... raditional data channels (TDChs), two additional channels, called quantum signal channels (QSChs) and public interaction channels (PIChs), are required to support the secure key synchronization. How to allocate network resources to QSChs, PIChs, and TDChs is emerging as a novel problem for the design of a security-guaranteed optical network. This article addresses the resource-allocation problem in optical networks secured by QKD. We first discuss a possible architecture for a QKD-enabled optical network, where a software-defined networking (SDN) controller is in charge of allocating the three types of channels (TDCh, QSCh, and PICh) over different wavelengths exploiting wavelength-division multiplexing (WDM). To save wavelength resources, we propose to adopt optical time-division multiplexing (OTDM) to allocate multiple QSChs and PIChs over the same wavelength. A routing, wavelength, and time-slot assignment (RWTA) algorithm is designed to allocate wavelength and time-slot resources for the three types of channels. Different security levels are included in the RWTA algorithm by considering different key-updating periods (i.e., the period after which the secure key between two end-points has to be updated). Illustrative simulation results show the effects of different security-level configuration schemes on resource allocation.