Wireless home automation networks are one example of how wireless technologies may soon become part of our daily life, yet security in existing products is woefully inadequate. An important problem in this area is the question of secure key distribution. In this paper we present a key-distribution scheme geared towards home automation networks, but applicable to other networks with related properties as well. Our approach uses a decentralized scheme that is designed to work on resource-poor devices, allows easy addition and removal of devices and limits the workload on the end user while guaranteeing the secrecy of the exchanged keys even in the presence of subverted nodes.