Bicom is a data compressor in the PPM family. It is freely available and Open Source. Its most unique characteristic is that compression with bicom is completely bijective -- any file is a possible bicom output that can be decompressed, and then recompressed back to its original form. Of course, any file is also a possible bicom input that can be compressed, and then decompressed back to its original form. To support encryption applications, bicom also includes a passphrase-protection option that will automatically encrypt after compressing, or decrypt before decompressing.
