[Retracted] A Comprehensive Survey on Sharding in Blockchains
Table 1
Description of scalability solutions.
No.
Category
Layer
Solution
Description
1
Scaling on-chain
Data layer solutions
Expand block
Increasing block size
2
Segregated Witness
Isolating digital signatures and increasing the block size in disguise
3
Directed acyclic graph (DAG)
Changing chain structure to net structure
4
Network layer solutions
Sharding
Parallel processing of transactions in shards to improve processing efficiency
5
Consensus layer solutions
BFT consensus
Reaching consensus through voting
6
Non-BFT consensus
Reducing block verification propagation time and consensus formation time by reducing the complexity of the consensus algorithm and reducing the number of propagation nodes
7
Hybrid consensus
Combining multiple consensus algorithms
8
Scaling off-chain
Layer 2 solutions
State channels
Transferring part of the transaction to the state channel, which can be opened and closed at any time
9
Side chain
Transferring transaction to the side chain and processed by the root chain only when fraud occurs
10
Cross-chain
Realizing transactions off-chain from a cross-chain perspective
11
Off-chain computation
Executing complex transactions off-chain, and the result is returned to the chain
12
Scaling on Layer 0
Layer 0 solutions
BDN/bloXroute
Improving the scalability of the blockchain by modifying and optimizing the underlying protocol, without affecting the existing blockchain