KGB archiver

KGB archiver is an Open Source archiver utility based on PAQ6 Compression Algorithm with an powerful AES-256 Encryption & available for both Windows and Linux platform.  It can compress your 1GB File to 10 mb only.. [In some cases, it can't]
It is Developed By -- Tomasz Pawlak. 

This Software has also several limitations such as :-

 > High Compression level is not seen while compressing files onto.zip format.
> Compressed files can only be Decompressed with KGB Archiver.