3-Heights™ PDF Security Shell - PDF Tools AG

3-Heights PDF Security Shell, Version 4.2 Page 26 of 35
July 8, 2013
Example: Overwrite the default producer:
pdfsecure –id Producer=MyProgram in.pdf out.pdf
-k Set the Length of the Encryption Key
The key length is a determining factor of the strength of the encrypting algorithm and the amount of time
to break the cryptographic system. For RC4 the key length can be any value from 40 to 128 that is a
multiple of 8. For AESV2 the key length is automatically set to 128, for AESV3 to 256.
Notes:
Certain PDF viewers only support 40 and 128 bit encryption. Other tools, such as the 3-Heights
tools also support other encryption key lengths.
256 bit encryption requires Acrobat 9 or later.
If the selected permission flags require a minimum key length, the key length is automatically
adjusted (e.g. to 128 bits)
-o Set Owner Password
The owner password is required to set any permission flags. On order to change the permission flags, the
owner password must be provided. The owner password can also be used to open user password
protected documents.
If no owner password is provided, the user password is used instead.
Example: Set the owner password to "owner".
pdfsecure –o owner in.pdf out.pdf
-p Set the Permission Flags
This option sets the permission flags. If any permission flag other than -1 is set, the document is
encrypted. By default no encryption is applied. If no permission flags are set, but either an owner or a user
password is set, all permissions are granted.
The permissions that can be granted are listed in the table below.
Table: Permission Flags
Parameter Description Bit
p allow printing (low resolution) 3
m allow changing the document 4
c allow content copying or extraction 5
o allow commenting 6
f allow filling of form fields 9
s allow content extraction for accessibility 10
a allow document assembly 11
d allow high quality printing 12
-1 default no encryption
0 allow nothing (no permissions are granted) none
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