2022/06/23 by Bennet Yee, Yee, Bennet · 1 citation
Computer Science · #Blockchain Technology Applications and Security #Cryptography and Security (cs.CR) #FOS: Computer and information sciences #Network Security and Intrusion Detection #Spam and Phishing Detection
paper · pdf · doi:10.48550/arxiv.2206.11974
openalex publication_date 2022/06/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The adversary's goal in mounting Long Range Attacks (LRAs) is to fool potential victims into using and relying on a side chain, i.e., a false, alternate history of transactions, and into proposing transactions that end up harming themselves or others. Previous research work on LRAs on blockchain systems have used, at a high level, one of two approaches. They either try to (1) prevent the creation of a bogus side chain or (2) make it possible to distinguish such a side chain from the main consensus chain. In this paper, we take a different approach. We start with the indistinguishability of side chains from the consensus chain -- for the eclipsed victim -- as a given and assume the potential victim will be fooled. Instead, we protect the victim via harm reduction applying "short leashes" to transactions. The leashes prevent transactions from being used in the wrong context. The primary contribution of this paper is the design and analysis of leashes. A secondary contribution is the careful explication of the LRA threat model in the context of BAR fault tolerance, and using it to analyze related work to identify their limitations.