SCN 2016 will have two invited speakers:
|Aggelos Kiayias (University of Edinburgh, UK)
Title:Foundations of Blockchain Protocols
Abstract:The bitcoin system is a remarkable solution. But to what problem? The rise of bitcoin and other cryptocurrencies puts forth a wealth of interesting questions in distributed systems and cryptography that relate to building decentralized systems. We initiate a formal investigation of this class of protocols and of their basic properties. The core of the bitcoin protocol can be abstracted in a simple algorithmic form that has been termed the bitcoin backbone in . This work also provided a synchronous model for the analysis of the protocol. This algorithmic abstraction and modeling enabled the expression of simple provable properties about the blockchain data structure maintained by the protocol called chain quality, common prefix and chain growth. In this model, the concept of a robust transaction ledger can also be de- fined and analyzed as captured by its two basic properties, persistence and liveness. Given the above we show how a robust transaction ledger can be reduced to a blockchain protocol that satisfies these simple prop- erties, cf. . Alternative proof strategies are possible and will be also examined. Given our formal definition of the robust transaction ledger problem, one can ask next whether the bitcoin backbone is the optimal solution. One important aspect of efficiency is the overhead to confirm transactions in the presence of an adversary, cf. , which is intimately related to the liveness of the ledger. Alternative designs such as GHOST used in the Ethereum system, are possible and will be analyzed and compared within the model with respect to their security and efficiency characteristics. Finally, the relation of a robust transaction ledger to the consensus prob- lem will be also examined and we will consider a number of model exten- sions that include rational players and dynamically changing user sets.
|Rafael Pass (Cornell University and Cornell NYC Tech., USA)
Title:Cryptography and Game Theory
Abstract: Cryptographic notions of knowledge consider the knowledge obtained, or possessed, by computationally-bounded agents under adver- sarial conditions. In this talk, we will survey some recent cryptographically- inspired approaches for reasoning about agents in the context of game- theory and mechanism design (where agents typically are modelled as computationally unbounded).