XlogicX
Saturday, August 16, 2025: 3:00 pm (Tobin 201/202): When you pop the hood of RFC 1951 (DEFLATE), there lies an interesting playground that would be otherwise unseen in the context of compression use cases. This talk will address many aspects of the ubiquitous DEFLATE compression, none of which involve compressing data! "Designer Compression" scenarios will be explored, such as blocks of DEFLATE data that can be fully ASCII printable, contain no data, buffer underflow access of nulls, and even apply forms of recursion. We will also see forensic data extraction from compressed fragments, employ difficult to detect watermarking, demo a covert channel PoC (deflate in http), and forever-cookies. The presentation style will take a high-level first pass and then dig into the technical details with the time left.