Table 21 – Additional encryption dictionary entries for the standard security handler

Key

Type

Value

R

number

(Required) A number specifying which revision of the standard security handler shall be used to interpret this dictionary:

2 if the document is encrypted with a V value less than 2 (see Ta b l e 20 ) and does not have any of the access permissions set to 0 (by means of the P entry, below) that are designated “Security handlers of revision 3 or greater” in Ta b l e 22

3 if the document is encrypted with a V value of 2 or 3, or has any “Security handlers of revision 3 or greater” access permissions set to 0

4 if the document is encrypted with a V value of 4

O

string

(Required) A 32-byte string, based on both the owner and user passwords, that shall be used in computing the encryption key and in determining whether a valid owner password was entered. For more information, see 7.6.3.3, "Encryption Key Algorithm," and 7.6.3.4, "Password Algorithms."

U

string

(Required) A 32-byte string, based on the user password, that shall be used in determining whether to prompt the user for a password and, if so, whether a valid user or owner password was entered. For more information, see 7.6.3.4, "Password Algorithms."

P

integer

(Required) A set of flags specifying which operations shall be permitted when the document is opened with user access (see Ta b l e 22 ).

EncryptMetadata

boolean

(Optional; meaningful only when the value of V is 4; PDF 1.5) Indicates whether the document-level metadata stream (see 14.3.2, "Metadata Streams" ) shall be encrypted. Conforming products should respect this value.

Default value: true.