OpenPGPASCIIarmoring

OpenPGP ASCII armor is a text encoding defined by the OpenPGP standard for representing binary OpenPGP data as printable ASCII. It enables the transmission of OpenPGP packets through channels that may not preserve binary data, such as email, chat, or paste buffers.

An armored block begins with a header line such as -----BEGIN PGP MESSAGE BLOCK----- and ends with a corresponding -----END PGP MESSAGE BLOCK----- line. Blocks indicate different payload types, including MESSAGE, PUBLIC KEY BLOCK, SECRET KEY BLOCK, and SIGNATURE. Inside the block, optional header fields (for example Version: and Comment:) precede a blank line, after which the payload is provided as base64-encoded data, typically wrapped to fixed column widths. The binary data is augmented with a 24-bit CRC checksum to help detect errors after decoding.

The ASCII armor is text-only, and when decoded by an OpenPGP implementation, the original binary packets are recovered and can be processed by the recipient, who may verify signatures, decrypt content, or import keys. The format is designed for interoperability across OpenPGP-compliant tools such as GnuPG and other OpenPGP implementations.

Usage notes: ASCII armor should be used when the transport medium is not binary-safe; however, it does not replace cryptographic protections. The underlying cryptographic operations (encryption, signing) remain the source of security; armor only provides a portable encoding and an integrity check. Care should be taken to preserve line breaks and header content to maintain compatibility across tools.