Quantum key distribution (QKD) is a new and promising approach for secure k
ey distribution based on the physical laws of quantum mechanics. This paper
describes the software architecture and the algorithms used in the protoco
l of a QKD system, called Eqcspot, developed as an industrial application.
The software system for the transparent key exchange consists of two applic
ations running on two PCs that communicate through a message and queuing pr
oduct, MessageWare Plus, on a LAN. The system interacts with the quantum ch
annel through a software library and exchanges data on the net. The final u
ser can interact with the system very easily thanks to a simple GUI client
component. The key distillation algorithm used in the system is briefly des
cribed in the paper. The quantum channel (QC) software library is a highly
generalized module for different schemes of QC driver implementations. Fina
lly the paper describes some initial results and future expansions of the s
ystem.