Mitigations on Sybil-Based Double-Spend Attacks in Bitcoin

Abstract

Double-spending is a potential flaw in cryptocurrencies. In recent years, double-spend attacks have caused severe economic damage to many Bitcoin consumers, thus double-spending problems have attracted wide attention. Studying related countermeasures and mitigations against such attacks is imperative. In this article, we briefly introduce a new form of combined attack: double-spending with a Sybil attack in the Bitcoin network and discuss how to mitigate it. We propose two mitigations such as charging an identity fee and setting a deadline to defend against this attack, and we evaluate the effect of these two mitigations through an economic analysis.