Notes: http://nil.csail.mit.edu/6.5840/2024/notes/l-sundr.txt
Video: https://youtu.be/FxwjSs_xSBM
Prep:
- Introduction
- Setting
- Focus
- Big Idea
- Why fetches in log?
- Fork Consistency
- Detecting forks
- Snapshots
- Version vectors
- Summary
Introduction
decentralized systems ⇒ no central point of trust
byzantine participants
SUNDR 2004
security
signed log (git, bitcoin, keybase/zoom)
Setting
Network FS
https://excalidraw.com/#json=9S21qWUdzUSAqm6qUtd0v,SHUVP7w8YsDXPl9nyFHr7w
Focus
Integrity, not confidentiality
Big Idea
signed log of operations
just a conceptual idea as practically, there’s so much overhead and not efficient
Why fetches in log?
Fork Consistency
Split brain ⇒ diff forks with diff commits
Detecting forks
- out of band communication
- timestamp box
when detected multiple forks, settle on one (bitcoin)
Snapshots
per user view
Version vectors
reader gets the latest version which will include every op in log
Summary
byzantine participants
signed log