Talks@DI/LaSIGE

Distributed Trust - From Byzantine Consensus to Blockchain

Sala 6.2.56, FCUL, Lisboa

Por Christian Cachin (IBM Research Zurich).

Although practical Byzantine consensus protocols have been available for two decades, they have never been deployed in production until very recently. The widespread interest in cryptocurrencies and blockchains has changed this. A blockchain is a distributed system for executing and recording transactions, which is maintained by many nodes without a central authority.  All nodes collaboratively validate the information to be included in the blockchain through cryptography and distributed consensus. Blockchains offer resilience and security based on the collective trust placed in the nodes maintaining it. This presentation will revisit protocols for Byzantine consensus and explore older and newer protocols that power blockchains. The talk also presents Hyperledger Fabric, a modular and extensible blockchain platform that is developed open-source under the Hyperledger Project and which was originally contributed by IBM. Fabric introduces a novel architecture for building resilient distributed systems that differs from the conventional paradigm, in order to accommodate flexible trust models, to cope with non-determinism, and to prevent resource exhaustion. There are currently several hundred prototypes, proofs-of-concept, and production systems of distributed ledger technology that use Fabric as a platform for distributing trust over the Internet.

Short Bio: Christian Cachin is a cryptographer and computer scientist interested in distributed computing, cryptographic protocols, and security, working 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. An IEEE Fellow, ACM Distinguished Scientist, and recipient of multiple IBM Outstanding Technical Achievement Awards, he has co-authored a textbook on distributed computing titled "Introduction to Reliable and Secure Distributed Programming". Currently he serves as the President of the International Association for Cryptologic Research (IACR). In addition to many cryptographic protocols that he has developed, particularly for achieving consensus and for executing distributed cryptographic operations over the Internet, he has also contributed to standards in storage security and key management. His current research addresses blockchains, the security of cloud computing, secure protocols for distributed systems, and cryptography.

14h00
Departamento de Informática / LaSIGE - Laboratório de Sistemas Informáticos de Grande Escala