Ruben Recabarren Velarde
Knight Foundation School of Computing and Information Sciences
Ruben Recabarren is a PhD candidate in Computer Science at the Knight Foundation School of Computing and Information Sciences (KFSCIS), Florida International University (FIU), under the direction of Dr. Bogdan Carbunar in the CaSPR lab. His research interests are in distributed ledger technologies, secure communication systems and vulnerability research. He earned a BSc. in Computer Engineering from Universidad Simon Bolivar in Caracas, Venezuela; and a MSc. in Cybersecurity from Florida International University.
Distributed Ledger Technologies (DLTs) have emerged as a new platform for building distributed systems. Our thesis is that Satoshi cryptocurrencies, i.e., Bitcoin and its variants, can be used to endow popular distributed services with strong security, privacy, and censorship resistance properties that evade many current solutions. To this end, we first study and report privacy and integrity vulnerabilities of Stratum, the de-facto pooled mining protocol. We design and implement Bedrock, a solution that secures Stratum at a small computational overhead. Second, we build DLSS, a distributed ledger storage system that embeds client content into Satoshi transactions and organizes it for fast search, recovery and reconstruction among hundreds of millions of financial transactions. Further, we leverage our blockchain-writing constructs to introduce a novel perspective for traditionally hard problems of censorship resistance, private e-mail and secure port-knocking with surreptitious authentication and logging.
We evaluate Bedrock in the live Bitcoin ecosystem, and show that it achieves orders of magnitude better performance than TLS or blanket encryption. We prove the security, privacy and anonymity of our smart contracts, and argue they impose unpalatable collateral damage to would-be censors. We evaluate our blockchain-writing constructs by persisting hundreds of MBs of BBC news stream articles and censored software in the live Litecoin blockchain, where they are available to access for free anywhere in the world. We show that our solutions achieve storage throughput, blockchain utilization, and cost efficiency that improve by 2-4 orders of magnitude on state-of-the-art blockchain-writing solutions.