# EPF - Update 16 Due to some professional commitments I wasn't able to work on my fellowship project with full capacity. I have however found myself in a more relaxed schedule now eager to get back on track with my project. I was last getting a deep academic understanding of dynamically available protocols, ebb and flow protocols and safety of distributed networks. The initial goal was to try to come up with a fork choice design different from the GHOST model. It was understood back then that this would be an ambitious task (and somewhat intimidatihg as well). Initial discussions with Francesco also revealed a pattern in dynamically availbe protocols which was interesting. It appears that all three of these properties cannot be met simaltaneously. - Reorg resilliance (nakamoto consensus isn't) - Subsampling/committees friendly (RLMD-GHOST isn't) - Asynchrony Resilliance (Goldfish and other dynamic quorum protocols aren't) I have already done a decent amount of research around fork choice rules and exploring the above statement also seems like a valuable contrinution to me. Although formalising a proof for or against the "trilema" is non-trivial, analysis around the problem and discovering patterns is a task that I feel is tangibe and valuable. ### This Week I have picked up from where I left off. Understanding the formal defitions of the above properties and understanding reorg attacks that happen in fork choice rules like longest chain. Went through the following resources: https://eprint.iacr.org/2016/918.pdf https://ethresear.ch/t/attacking-gasper-without-adversarial-network-delay/10187 https://ethresear.ch/t/reorg-resilience-and-security-in-post-ssf-lmd-ghost/14164 https://www.paradigm.xyz/2021/07/ethereum-reorgs-after-the-merge Next steps would be to analyse Goldfish, RLMD-GHOST, total-order broadcast, DAG based protocols, etc to analyse patterns for the above properties. Also went through formal CAP and distributed system proofs to see how to formalise such impossibilities. https://arxiv.org/pdf/2006.10698 https://www.the-paper-trail.org/post/2008-08-13-a-brief-tour-of-flp-impossibility/