PEA - PeaZip Archive File Format
What is a PEA file?
A file with .pea extension, acronym for Pack, Encrypt, and Authenticate, is a zip archive created with PeaZip archiving software application. It features compression and multiple volume output, and offers a flexible security model through Authenticated Encryption and cryptography. This provides both privacy and authentication of the data. The PeaZip utility is available as open-source engine that can be compiled for different OS as per requirements.
PEA File Format
The PEA file format specifications are publicly available for developer’s reference. PEA archives are binary files with flexible security model and redundant integrity checks ranging from checksums to cryptographically strong hashes. This defines three different levels of communication to control:
- Streams - the actual output data stream that is formed by multiple input files and can be written written to multiple output volumes
- Objects - input files and folders sent to .pea archive
- Volumes - output archive file that can be spanned to user defined size
Each one of these are optional and can be incorporated as per user requirements. The PEA file format can store a single stream containing unlimited objects. Each stream is up to 2^64 bytes in size.
PEA files offer optional integrity check and authenticated encryption using AES in EAX or HMAC mode, alternatively Twofish and Serpent in EAX mode.
PEA Archive Header
The archive header is 10 bytes and is structured as follow.
| Bytes | Description |
|---|---|
| 1 | Magic byte field for file format disambiguation: $EA |
| 1 | Version Number |
| 1 | Revision Number |
| 1 | Volume control scheme |
| 1 | Declaring the OS where the stream was built |
| 1 | Declaring OS date and time encoding |
| 1 | Declaring objects name character encoding |
| 1 | Declaring CPU type (encoded in 7 bit) and endianness (in msb) |
| 1 | Reserved for future use |