Title: Wireless Protocol Validation Under Uncertainty and Scaling Education

Abstract: Wireless communication is enabling the rapid proliferation of new types of custom wireless devices, such as the Google ChromeCast, XBox controllers, and FitBit. These new devices frequently operate using custom wireless protocols, resulting in a growing number of protocol implementations that need to be tested. Traditional black box testing approaches are tedious and error prone, and may not successfully test all conditions experienced in the wild. This has resulted in multiple embarrassing connectivity flaws in shipped products.

In the first part of this talk, I will describe our system, VeriFi, which is the first systematic sniffer-based model-guided runtime verification framework for wireless protocol implementations. Compared to existing approaches, VeriFi achieves better coverage and reproducibility while completing more rapidly and requiring less developer effort. VeriFi does not require access to implementation source code or debugging capabilities, which are often missing in practice. Instead, it utilizes an additional wireless device on sniffer to both record and manipulate wireless communication with the device under test (DUT). To improve protocol coverage, VeriFi can selectively jam these transmissions to force the DUT to execute error handling logic that might not normally be triggered in the testing environment. When testing is complete, VeriFi uses packet exchanges recorded by the sniffer to determine whether the implementation matches the specification.

In the second part of this talk I will describe several approaches I have pursued to scaling education. These include novel automated grading approaches for teaching operating systems and new large-format flipped courses.

Biography: Geoffrey Challen leads the blue systems group (www.bluegroup.systems), a talented group of systems designers and hackers located at the University at Buffalo. He also directs the PhoneLab Smartphone Platform Testbed (phone-lab.org). His group focuses on harnessing the power of the billions of deployed smartphones, which together comprise the largest distributed system ever built. He also teaches courses on computer operating systems (ops-class.org) and the internet (internet-class.org). He received both undergraduate and doctoral degrees from Harvard University, where he worked with Matt Welsh (www.mdw.la) deploying sensor networks on active volcanos.