B1 is an open archive file format that supports data compression and archiving. B1 files use the file extension ".b1" or ".B1" and the MIME media type application/x-b1. B1 incorporates the LZMA compression algorithm.B1 archive combines a number of files and folders into one or more volumes, optionally adding compression and encryption. Construction of the B1 archive involves creating a binary stream of records and building volumes of that stream. The B1 archive format supports password-based AES-256 encryption.B1 files are created and opened with its native open-source B1 Pack Tool, as well as B1 Free Archiver utility. Please note that the Windows B1 Free Archiver utility is normally installed with spyware that is not mentioned in the programs installation wizard, however this spyware can