Professor Silvio Micali, winner of the 2012 Turing Award, started off GYSS 2019 with his opening plenary on Distributed Ledgers and Blockchains. He discussed the trilemma of blockchain today - that most blockchains are said to be able to fulfil at most two of the three wanted properties: security, scaleability and decentralisation.

His solution is a pure proof-of-stake protocol that deploys Verifiable Random Function (VRF) to solve the bottleneck of blockchain, addressing all three issues in the trilemma. A random user is chosen to propose the next block of data in the blockchain, and then a committee of other users is randomly selected to agree on and verify the block. In both cases, the probability of a user being chosen is proportionate to the amount of money he or she has in the system.

Professor Micali said: “We built bridges in the past to allow people from different sides of a river to meet and trade. Blockchain will be as useful to bridge us as humanity as any physical infrastructure. If we choose and construct it in the right way, it will help our planet for many years to come.”