A Comparison of Layer 2 Techniques for Scaling Blockchains

Abstract

Since the creation of Bitcoin, back in 2009, many other cryptocurrencies have appear, and its usage has been growing year after year. With this huge popularity, doubts about the ability of blockchains to become worldwide payment systems (or even universal mediums for general decentralised systems) begin to arise and, with them, solutions started to be explored. In this paper we first explain the blockchain scalability problem and then present a brief review and a comparison among some of the state-of-the-art techniques that are used to scale blockchains on Layer 2 (or off-chain), analysing properties related to their Usability, Security and Cost.