| Speaker Affiliation | IBM Research, Zürich |
| Start | 12.06.2015, 15:00 Uhr |
| Location | TU Braunschweig, Informatikzentrum, Mühlenpfordtstraße 23, 1. OG, Hörsaal M 161 |
| Invited by | Prof. Dr. Rüdiger Kapitza |
| The overhead of Byzantine fault tolerant (BFT) storage is a primary concern that prevents its adoption in practice. The cost stems from the need to maintain at least 3t + 1 copies of the data at different storage replicas in the asynchronous model, so that t Byzantine replica faults can be tolerated. This work introduces MDStore, the first fully asynchronous BFT storage protocol that reduces the number of replicas that store the payload data to as few as 2t + 1 and maintains metadata at 3t + 1 replicas on (possibly) different servers. At the heart of MDStore lies a metadata service built upon a new abstraction called "timestamped storage." Timestamped storage allows for conditional writes (facilitating the implementation of the metadata service) and has consensus number one (making it implementable with wait-free semantics in an asynchronous system despite faults). In addition to its low replication overhead, MDStore offers strong guarantees by emulating a multi-writer multi-reader atomic register, providing wait-free termination, and tolerating any number of Byzantine readers and crash-faulty writers. Based on joint work with Elli Androulaki, Dan Dobre, and Marko Vukolić. Christian Cachin is a researcher in cryptography and security at IBM Research - Zurich. He graduated with a Ph.D. in Computer Science from ETH Zurich and has held visiting positions at MIT and at EPFL. Presently he serves as the President of the International Association for Cryptologic Research (IACR). An IEEE Fellow, ACM Distinguished Scientist, and recipient of multiple IBM Outstanding Technical Achievement Awards, he has co-authored the book "Introduction to Reliable and Secure Distributed Programming" and contributed to the OASIS Key Management Interoperability Protocol (KMIP) standard. His current research addresses the security of cloud computing, secure protocols for distributed systems, and cryptography. | |