Poster: Bitcoin Meets Collective Signing

While showing great promise, Bitcoin requires users to wait tens of minutes for transactions to commit – even then offering only probabilistic guarantees. This work introduces ByzCoin, a novel Byzantine consensus protocol that leverages scalable collective signing to commit Bitcoin transactions irreversibly within seconds. ByzCoin achieves Byzantine consensus while preserving Bitcoin’s open membership by dynamically forming hash power-proportionate consensus groups representing recently-successful block miners. ByzCoin employs communication trees and achieves a throughput of up to 975 transactions per second (TPS), which is more than Paypal currently handles, with confirmation latencies of 15-20 seconds while mitigating double spending and selfish mining attacks.