A quick technical review 🧵 on AT Protocol (Bluesky) and Farcaster.

Both protocols have quite similar objectives, but they have very different design.

First, identity. Both want account portability where user can migrate identity to a new service provider without existing server’s cooperation (unlike Fediverse). 

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By the way, both protocols use merkle tree for synchronization. ATP uses Merkle Search Tree while FC uses Merkle Patricia Trie. But they differs in that each ATP user has a individual tree and user signs the tree’s root, while FC has a tree that represents the world’s state and user signs their own messages. 14/n

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MST is self-balancing and the depth of the tree is close to log n. MPT is not self-balancing, when the keys are not uniformly distributed (like the case of Farcaster), the tree structure will be suboptimal. Hence, MST is faster to look up in theory.

Curious if there are advantages of MPTs vs. MSTs for sync? Or could it make sense for FC to use MSTs for world state?