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Typical Internet of Things (IoT) and smart home environments are composed of smart devices that are controlled and orchestrated by applications developed and run in the cloud. Correctness is important for these applications, since they control the home's physical security (i.e. door locks) and systems (i.e. HVAC). Unfortunately, many smart home applications and systems exhibit poor security characteristics and insufficient system support. Instead they force application developers to reason about a combination of complicated scenarios-asynchronous events and distributed devices. This paper demonstrates that existing cloud-based smart home platforms provide insufficient support for applications to correctly deal with concurrency and data consistency issues. These weaknesses expose platform vulnerabilities that affect system correctness and security (e.g. a smart lock erroneously unlocked). To address this, we present OKAPI, an application-level API that provides strict atomicity and event ordering. We evaluate our work using the Samsung SmartThings smart home devices, hub, and cloud infrastructure. In addition to identifying shortfalls of cloud-based smart home platforms, we propose design guidelines to make application developers oblivious of smart home platforms' consistency and concurrency intricacies. 

Mobile web traffic and application data demands are growing at a rapid rate and are at odds with resource-constrained, data-capped, wireless mobile devices. Data compression can be used to reduce web traffic, save energy, and make network transfers faster. Compression can, however, hurt performance if not used judiciously. We propose Locomotive, a library that improves the performance of network transfers in wireless mobile networks by employing selective compression based on data type and network conditions. We demonstrate that Locomotive improves performance of web transfers by roughly 12-24% while reducing data usage by 39%.