[irwt]

One of the authors of the paper here. We did not cite this work, because it has nothing to do with what we're proposing. One should not confuse Merkle multiproofs with sparse Merkle trees. We mentioned that in the paper as well. I do know that Vitalik once proposed the idea of sparse Merkle multiproofs somewhere informally, and we would love to cite that if someone could provide a link to that. But regarding the compact sparse Merkle tree, just because this paper shares some words in the title, does not make it the same thing.

[decentralised]

I vaguely remember Vitalik mentioning multiproofs in the context of stateless clients for Ethereum 2.0, but this is what I could find: https://ethresear.ch/t/open-research-questions-for-phases-0-... and the code: https://github.com/ethereum/research/tree/master/merkle_tree

I also found a good article introducing multiproofs from Jim McDonald here: https://www.wealdtech.com/articles/understanding-sparse-merk...

[irwt]

Thank you for the links, I will try and edit the paper in the upcoming days to include Vitalik's mentioning. Jim McDonald's article is also wonderful, we referenced it multiple times and experimented quite a lot with his Merkle tree repo: https://github.com/wealdtech/go-merkletree

[remcob]

I heard about about a similar (same?) method before and wrote about it here: https://ethresear.ch/t/optimizing-merkle-tree-multi-queries/...

In the comments Vitalik links to his implementation.