Author: Aanavi Dalmia
Last updated: 2026-06-27
The objective of Week 4 is to extend the blockchain growth model developed in Week 3 by modelling the communication layer and the adversarial observer. While Week 3 focuses on how blocks are produced through stake-weighted leader election, Week 4 investigates how these blocks propagate through the network and whether the resulting communication patterns leak information about the identity or stake of validators.
The project specification identifies three major components that must be developed:
These components are closely related. Privacy cannot be evaluated without first defining how messages propagate through the network and what information an adversary is assumed to observe.
Once a validator wins leader election, it broadcasts a block proposal to every other validator. The communication network therefore determines how quickly information spreads across the blockchain.
Although the network forwards messages hop-by-hop, the objective of this project is not to simulate every forwarding event individually. Instead, the focus is on broadcast latency, since propagation time is the information directly observable by passive adversaries.
Consequently, modelling communication latency provides sufficient information for analysing anonymity while avoiding unnecessary simulation complexity.
Validators are represented as vertices of a peer-to-peer communication graph.
Edges represent communication links between validators.
A random regular graph is used because every validator maintains approximately the same number of neighbours, providing a simplified yet well-connected communication topology while avoiding artificial hub nodes.