# EPF - Update 8 The goal for the next 4-6 weeks would to be get myself deeply familiarised with the concepts of dynamic availability, ebb and flow protocols, GHOST based attacks and existing ssf research. This week I mainly focused on fundamental concepts for distributed systems like network synchrony and what partial asynchrony means. Also started reading up on dynamically available protocols. "The Sleepy Model of Consensus" showed that nakamoto consensus was the first dynamically available protocol. Several researchers have shown it to be safe under synchrony. "Resource Pools and the CAP Theorem" established a dycotimy between availabilty and finality meaning a consens protocol can only acheive one. This gave rise to Ebb and Flow protocols like Gasper. ![Screenshot 2024-08-08 at 8.19.52 PM](https://hackmd.io/_uploads/SkMQiIG50.png) Ebb and flow protocols outputs an available and a finalised ledger with the following properties: - the finality ledger is safe at all times given a portion of nodes are corrupt (33% for Gasper) - the availability ledger is safe and live at all times given a portion of active nodes are corrupt (50% for longest chain consensus) - finality ledger is a prefix of available ledger at all times ## Roadmap to Week 9 Need to gain a deeper and more formal understanding of how dynamically available protocols work. Going to go through some of these protocols: - GoldFish: https://fc24.ifca.ai/preproceedings/7.pdf - RMLD-GHOST: https://eprint.iacr.org/2023/279.pdf - Streamlining Sleepy Consensus: https://arxiv.org/pdf/2310.11331 Also want to understand a different family of protocols called Snap and Chat that are similar to Ebb and Flow models. ## References - https://decentralizedthoughts.github.io/2020-11-01-ebb-and-flow-protocols-a-resolution-of-the-availability-finality-dilemma/ - https://decentralizedthoughts.github.io/2019-06-01-2019-5-31-models/ - https://decentralizedthoughts.github.io/2019-09-13-flavours-of-partial-synchrony/ - https://decentralizedthoughts.github.io/2019-11-29-Analysis-Nakamoto/ - https://www.the-paper-trail.org/post/2008-08-13-a-brief-tour-of-flp-impossibility/ - https://arxiv.org/pdf/2006.10698 - https://arxiv.org/pdf/2009.04987 - https://eprint.iacr.org/2016/918.pdf