With a similar idea in mind, I have experimented with bloom filters on my blossom server implementation. https://almond.slidestr.net/_bloom there is also a serverside check to debug: https://almond.slidestr.net/_bloom?test=3deb9daf761c8d638f8ccda3523113b4eddbcf3391c469e8b12da53aa83bf47d6 I haven't really used it yet but my idea is to have "edge blossom servers" that proxy to "backend blossom servers" and the filter would be a great optimization if the proxy had knowledge where to find a specific blob. It could also be used in clients, to speed up failover to other blossom servers. Have to look into those binary fuse filters now.