PORTABLE DOCUMENT FORMAT FILE CUSTOM FIELD

摘要

Examples include assembly of a portable document format file including encrypted content, unencrypted content, and/or alternative content. In an example, metadata, data block(s), and a content map are signed and stored in, or assembled into, a custom field or fields of the portable document format file. The metadata, data block(s), and content map are encrypted and assembled into a custom field or fields of the portable document format file with an encrypted key or keys. Unencrypted and/or alternative content may also be stored in the assembled portable document format file.