# EPF - Update 17 Two main protocols to understand in this debate between asynchrony resilliance and sub committees is the comparison between GoldFish and RLMD-GHOST. ### GoldFish GoldFish is a drop in replacement for LMD-GHOST. It modifies the fork choice rule slighly to acheive a security guarantee. LMD-GHOST is a fork choice rule to choose the tip of the canonical blockchain based on votes. It's a greedy algorithm. A slot is assumed to be 2 delta long (assuming delta to be the maximum network delay in a synchronous environment) where the block proposer runs GHOST and adds their block to the tip. After delta, a small committee also runs GHOST to confirm that the block is proposed at the tip according to the votes. Goldfish adds another check by validators to run a T deep confirmation rule. This ensures reorg resillience. To keep this process efficient, only the preceding slots votes affect the protocol so only a few messages need to be buffered and merged. ![Screenshot 2024-10-09 at 1.29.37 PM](https://hackmd.io/_uploads/HJpxdh7ykg.png) The problem with GoldFish is the synchronous assumption. If the network faces partial asynchrony where messages are not delivered in delta time, then GoldFish will not receive the nessecary votes in slot t-1 to build slot t. ### RLMD-GHOST RLMD-GHOST relaxes vote expiry conditions of GoldFish and allows for votes from n most recent slots. This relaxation helps keep the protocol safe under asynchrony but does away with subsampling because it would reintroduce the possibility of ex-ante reorgs through accumulating votes from multiple committees. ### Next Week Based on current research, a dycotmity is apparent subsmapling and asynchrony resilliance in reorg resistance porotocols. Next steps would be to start formalising this pattern (if it does indeed exists or explore otherwise) and to also do a comparitive analysis of both these properties. ### References https://fc24.ifca.ai/preproceedings/7.pdf https://www.paradigm.xyz/2022/09/goldfish https://ethresear.ch/t/change-fork-choice-rule-to-mitigate-balancing-and-reorging-attacks/11127 https://arxiv.org/pdf/2302.11326 https://a16zcrypto.com/posts/videos/recent-latest-message-driven-ghost/