How Secure are Blockchain Systems?

Abstract

Blockchains are promising many applications in distributed computing systems, ranging from supply chain to critical infrastructure (e.g., cyber-physical systems). For foundations-driven guarantees of blockchain systems, a better understanding of their security is necessary. In this talk, we will explore questions surrounding the security of blockchain technology. As a distributed peer-to-peer system that relies in its operation on the behavior of peers, multiple security threats are outlined due to various fundamental realities, such as stale and orphan blocks, blockchain forks, selfish-mining, equivocation, and privacy-issues through blockchain ingestion. To this end, we proceed by presenting a systematic exploration of the attack surface of the blockchain technology from network and application standpoints and several potential solutions to address those attacks towards enabling a reliable use of blockchain for provenance applications. Specifically, we investigate the fundamental properties of the blockchain as distributed systems, and how they can be violated using various intended (due to malicious behavior) and unintended (due to reliability constraints) behaviors, and investigate how these attacks can be mitigated by enhancing the current protocols. We conclude with open questions and directions.