Security and Privacy of Blockchain-based Systems

Abstract

Blockchain technology began to reshape the world of distributed systems immediately after the publication of the white paper describing its architecture, released in 2008 by Satoshi Nakamoto. The possibility of storing data in a decentralized and immutable way, without relying on a trusted third party, offered a wide range of scenarios that affect different areas. Initially used to create revolutionary virtual payment systems, i.e., cryptocurrencies, blockchain architecture was then modified to suit different contexts. Although many applications are currently using blockchain effectively, unsolved security and privacy issues are slowing down its large-scale diffusion. This dissertation presents a research project focused on studying the role played by blockchain technologies in cyber-security. The research activities performed during several sub-projects began with a survey on cryptographic puzzles, one of the most important technological pillars of the original blockchain architecture presented by Nakamoto. We then exploited the knowledge acquired on the blockchain foundations to analyze users' privacy in the Bitcoin realm. In particular, we investigated Bitcoin transactions that diverge from the standard protocol, uncovering new behaviors never observed before. Finally, we studied a novel blockchain-enabled cyber-crime, called cryptojacking, that allows attackers to mine cryptocurrencies by stealing computational resources from unwitting users.

Date of Award	2021
Original language	American English
Awarding Institution	HBKU College of Science and Engineering