Abstract
In this paper we give a preliminary overview of the TClouds architecture, which is devoted to providing incrementally high levels of security and dependability to cloud infrastructures, in an open, modular and versatile way, based on the cloud-of-clouds paradigm. The TClouds architecture serves these objectives essentially by re-using and reconfiguring the same basic components, for example, intrusion-tolerant protocols (e.g., BFT). We exemplify concrete instantiations of the architecture and report on recently published proof-of-concept prototypes that validate the architecture's effectiveness.