# Module Cryptokit.Zlib

    module Zlib: sig .. end

The `Zlib` module supports the compression and decompression of data, using the `zlib` library. The algorithm used is Lempel-Ziv compression as in the `gzip` and `zip` compressors. While compression itself is not encryption, it is often used prior to encryption to hide regularities in the plaintext, and reduce the size of the ciphertext.

    val compress : ?level:int -> unit -> Cryptokit.transform

Return a transform that compresses its input. The optional `level` argument is an integer between 1 and 9 specifying how hard the transform should try to compress data: 1 is lowest but fastest compression, while 9 is highest but slowest compression. The default level is 6.

    val uncompress : unit -> Cryptokit.transform

Return a transform that decompresses its input.