Crypt::IDA is a Perl module that implements Rabin's Information Dispersal Algorithm. This is what's known as a "threshold system": a secret is divided into n shares with the property that any k (the "quorum" or "threshold") of those shares (with k <= n) can be combined at a later time to reconstruct the secret. The algorithm should be cryptographically secure in the sense that if fewer shares than the quorum k are presented, no information about the secret is revealed. The module uses Math::FastGF2 to efficiently implement the algorithm, making it suitable for securely sharing and distributing even large files. The Crypt::IDA::ShareFile module implements a file format for creating, storing, and distributing shares created with Crypt::IDA.
Various archive formats can be created, extracted, tested, listed, searched, compared, and repacked by patool. The advantage of patool is its simplicity in handling archive files without having to remember myriad programs and options. The archive format is determined by the file(1) program and as a fallback by the archive file extension. patool supports 7z (.7z), ACE (.ace), ADF (.adf), ALZIP (.alz), APE (.ape), AR (.a), ARC (.arc), ARJ (.arj), bzip2 (.bz2), CAB (.cab), COMPRESS (.Z), CPIO (.cpio), deb (.deb), DMS (.dms), FLAC (.flac), gzip (.gz), ISO (.iso), LRZIP (.lrz), LZH (.lha, .lzh), LZIP (.lz), LZMA (.lzma), LZOP (.lzo), RPM (.rpm), RAR (.rar), RZIP (.rz), SHN (.shn), tar (.tar), XZ (.xz), zip (.zip, .jar), and ZOO (.zoo) formats. It relies on helper applications to handle those archive formats (for example bzip2 for BZIP2 archives). The archive formats tar, zip, bzip2, and gzip are supported natively and do not require helper applications to be installed.