With shared dictionaries you can compress everything down to under a byte.
Just put the to-be-compressed item into the shared dictionary, somehow distribute that to everyone, and then the compressed artifact consists of a reference to that item.
If the shared dictionary contains nothing else, it can just be a one-bit message whose meaning is "extract the one and only item out of the dictionary".
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With shared dictionaries you can compress everything down to under a byte.
Just put the to-be-compressed item into the shared dictionary, somehow distribute that to everyone, and then the compressed artifact consists of a reference to that item.
If the shared dictionary contains nothing else, it can just be a one-bit message whose meaning is "extract the one and only item out of the dictionary".