Status: R

as a compression program, but there's a key difference: the text compressor *doesn't* need a key.

Sure, 12 14 16, etc., bits as in the classic unix compress program.

The encryption tool would have an interface like Boolean (*)( DataSource, DataSink, void*);

A compressor written to the same interface would never need to touch that third argument. Therefore, the second argument is "specifically designed" to permit an encryption tool to be used.

Not at all. coyping inbuf to output is a common practice, it's quite rare that you often compress in-place. /r$