OpenPGP is a long-standing cryptographic standard for encrypting data and, more commonly in software distribution, signing files and release metadata. A signature made with OpenPGP lets recipients verify that a file or release description was created by the expected maintainer and was not altered in transit. It is a legacy format, but it remains widely supported across package repositories, release pages, and verification tools.
In cyber security, OpenPGP matters because trust often depends on more than the installer itself. Defenders use it to confirm checksums, release notes, and downloadable artifacts; attackers try to exploit that trust by changing pointers, replacing signature files, or confusing users about which key to trust. If the signature workflow is strong, tampering is easier to detect. If the metadata around OpenPGP verification is weak, users may be guided to a malicious file even when the original package is untouched.