Even zlib looks to be a bit more complex than that when doing streams of packet data: http://www.bolet.org/~pornin/deflate-flush-fr.html http://www.bolet.org/~p

Even zlib looks to be a bit more complex than that when doing streams of packet data: http://www.bolet.org/~pornin/deflate-flush-fr.html http://www.bolet.org/~pornin/deflate-flush-fr.html There's also stuff like preset dictionaries and so on so string->string is just one part of the abstraction and isn't a full signature. Compression level's another. zlib's also not competitive in many scenarios, so it's only "done" for limited scope.