Mobile cyber-physical systems (M-CPSs) are envisaged as an integral part of our digital future. Dependability of M-CPSs is subject to timely, reliable, and secure information exchange among M-CPS entities. Information exchange provisioning in such systems is conventionally built with sole reliance on wireless connectivity. The conventional approaches, however, fail to efficiently exploit dynamism and heterogeneity, and to incorporate computing/cooperation as alternative system-wide tools for information exchange. To address these issues, we approach M-CPSs dependability from the information exchange perspective and define dependable-exchange-of-information (DeX) indicating collective M-CPS capability of information exchange provisioning. We then propose a cloud-based architecture for DeX provisioning as a service to facilitate versatile development of dependable M-CPSs.