IDEntry

Inheritance and contracts

Parent : PDF\Specification\SchemaEntry

Definition in the specification

Table 15 · Entries in the file trailer dictionary
ISO 32000-1:2008, §7.5.5 · PDF page 51 ↗

/ID array

(Required if an Encrypt entry is present; optional otherwise; PDF 1.1) An array of two byte-strings constituting a file identifier (see 14.4, "File Identifiers") for the file. If there is an Encrypt entry this array and the two byte-strings shall be direct objects and shall be unencrypted. NOTE 1 Because the ID entries are not encrypted it is possible to check the ID key to assure that the correct file is being accessed without decrypting the file. The restrictions that the string be a direct object and not be encrypted assure that this is possible. NOTE 2 Although this entry is optional, its absence might prevent the file from functioning in some workflows that depend on files being uniquely identified. NOTE 3 The values of the ID strings are used as input to the encryption algorithm. If these strings were indirect, or if the ID array were indirect, these strings would be encrypted when written. This would result in a circular condition for a reader: the ID strings must be decrypted in order to use them to decrypt strings, including the ID strings themselves. The preceding restriction prevents this circular condition.

Qualifier: Required if an Encrypt entry is present; optional otherwise; PDF 1.1

Conditional descriptions remain traceable. A definition alone does not implement a codec, a signature or every format mechanism. Read the coverage.

Construction

Inherited methods

Properties

Constants

'ID'

'15'

false