Bachelor/Master Thesis
Blockchain and BlockDAG Protocols
Blockchain protocols construct a chain of blocks that contain transactions. Miners produce these blocks and broadcast them to the network. Unfortunately, if the network is slow instead of a block following another block we can have two blocks following one single block. We need to agree on one of these blocks, in other words, we will discard one of these blocks (this phenomenon is known as a fork). To solve this inconvenience, so-called DAG (Directed Acyclic Graph) protocols were created as a possible successor of the usual blockchain protocols.
This project consists of a simulation of 4 of these protocols. Bitcoin [1] is considered as a representative of the usual blockchain and as the starting point of this project. Changing the longest chain rule of Bitcoin we will simulate GHOST [2]. GHOST will also work as a bridge to DAG protocols by the hand of GHOSTDAG[3]. GHOSTDAG consists of the direct transformation of GHOST into a DAG protocol. Via GHOSTDAG’s simulation, we will approach our last simulation: Conflux [4]. Conflux can be regarded as a generalisation of GHOSTDAG to include off main chain block into the transactions list.
This project aims to run simulations of these protocols and understand the basic properties and problems these protocols present.
[1] Bitcoin: A Peer-to-Peer Electronic Cash System. https://bitcoin.org/bitcoin.pdf
[2] Accelerating Bitcoin’s Transaction Processing. Fast Money Grows on Trees, Not Chains. https://eprint.iacr.org/2013/881
[3] PHANTOM, GHOSTDAG: Two Scalable BlockDAG protocols. https://eprint.iacr.org/2018/104.pdf
[4] Scaling Nakamoto Consensus to Thousands of Transactions per Second. https://arxiv.org/abs/1805.03870