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CHAPTER 3 Syntax
BIT POSITION MEANING
4 Modify the contents of the document by operations other than
those controlled by bits 6, 9, and 11.
5 (Revision 2) Copy or otherwise extract text and graphics from the
document, including extracting text and graphics (in support of ac-
cessibility to users with disabilities or for other purposes).
(Revision 3 or greater) Copy or otherwise extract text and graphics
from the document by operations other than that controlled by bit
10.
6 Add or modify text annotations, fill in interactive form fields, and,
if bit 4 is also set, create or modify interactive form fields (including
signature fields).
7–8 Reserved; must be 1.
9 (Revision 3 or greater) Fill in existing interactive form fields (includ-
ing signature fields), even if bit 6 is clear.
10 (Revision 3 or greater) Extract text and graphics (in support of ac-
cessibility to users with disabilities or for other purposes).
11 (Revision 3 or greater) Assemble the document (insert, rotate, or de-
lete pages and create bookmarks or thumbnail images), even if bit 4
is clear.
12 (Revision 3 or greater) Print the document to a representation from
which a faithful digital copy of the PDF content could be generated.
When this bit is clear (and bit 3 is set), printing is limited to a low-
level representation of the appearance, possibly of degraded quality.
(See implementation note 25 in Appendix H.)
13–32 (Revision 3 or greater) Reserved; must be 1.
Encryption Key Algorithm
As noted earlier, one function of a security handler is to generate an encryption
key for use in encrypting and decrypting the contents of a document. Given a
password string, the standard security handler computes an encryption key as
shown in Algorithm 3.2.
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