[1] B1 archive combines a number of files and folders into one or more volumes, optionally adding compression and encryption.
The B1 archive format supports password-based AES-256 encryption.
[2] B1 files are created and opened with its native open-source B1 Pack Tool, as well as B1 Free Archiver utility.
[3][4] B1 Pack is an open-source software project that produces a cross-platform command-line tool and a Java library for creating and extracting file archives in the B1 archive format.
[6] The B1 Pack Tool module builds a single executable JAR file which can create, list, and extract B1 archive files from a command-line interface.