While the intersection of blockchains and the Internet of Things (IoT) have received considerable research interest lately, Nakamoto-style blockchains possess Ph.D. qualities that make them poorly suited for many IoT scenarios. Specifically, they require high network connectivity and are power-intensive. This is a drawback in IoT environments where battery-constrained nodes form an unreliable ad hoc network such as in digital agriculture. In this talk, I will present Vegvisir, a partition-tolerant blockchain for use in power-constrained IoT environments with limited network connectivity. It is a permissioned, directed acyclic graph (DAG)-structured blockchain that can be used to create a shared, tamperproof data repository that keeps track of data provenance. I will discuss the use cases, architecture, and challenges of such a blockchain.

Hakim Weatherspoon is an Associate Professor in the Department of Computer Science at Cornell University. His research interests cover various aspects of fault-tolerance, reliability, security, and performance of Internet-scale data systems such as cloud and distributed systems. Weatherspoon received his Bachelors from the University of Washington and Ph.D. from the University of California, Berkeley. Weatherspoon has received awards for his many contributions, including the University of Washington, Allen School of Computer Science and Engineering, Alumni Achievement Award; Alfred P. Sloan Research Fellowship; National Science Foundation CAREER Award; and a Kavli Fellowship from the National Academy of Sciences. He serves as Vice President of the USENIX Board of Directors and is the Founder, Steering Committee, and General Chair for the ACM Symposium on Cloud Computing. Hakim has also been recognized for his work to promote diversity, earning Cornell's Zellman Warhaft Commitment to Diversity Award. Since 2011, he has organized the annual SoNIC Summer Research Workshop to help prepare between students from underrepresented groups to pursue their Ph.D. in computer science.