A Survey of Scalability Solutions on Blockchain

The blockchain is the distributed ledger technology, and the unchangeability is the main feature. However, the scalability is hindered to satisfy the characteristic. Nowadays, there are more and more attempts to put many applications on block-chains, but there are problems in actual use, for example, the low number of processing transactions per second (tps). Since solving these problems can increase the performance of the blockchain and reduce the cost, to solve them is one of the most important issues in the blockchain; And it is called the scalability issue. In this paper, we analyze methods that various attempts to solve it into following categories: On-chain, Off-chain, Side-chain, Child-chain and Inter-chain. We will analyze how these methods in each category work, what their pros and cons are, and finally compare which scalability issue has been resolved and their own features.