Security

pdfMachine supports PDF encryption, as defined in the "Adobe Portable Document Format Version 1.4".

Protect Document If checked enables the security features.

Encryption Key length RSA compatible encryption is used, with either 40 bit or 128 bit key lengths. NB. Acrobat Reader versions prior to version 5 only support 40 bit encryption. 128 bit encryption is more secure than 40 bit encryption.

User Password If supplied, then this password must be entered for the document to be opened. Applications like Acrobat Reader will prompt the user to enter this password prior to displaying the document. Longer passwords are more secure than shorter ones - up to a maximum size of 32 characters.

Owner Password If supplied, this password will have to be entered for users to change document Permissions. Permissions can be changed in programs such as Adobe Acrobat.

Permissions These control what access the user has to the document. NB. If no owner password is present then these permissions can be changed by anyone who can open the document (if they have the appropriate software). Beware; there are programs available that can remove these permissions from PDF documents without the need of an owner password.

Protect Document	If checked enables the security features.
Encryption Key length	RSA compatible encryption is used, with either 40 bit or 128 bit key lengths. NB. Acrobat Reader versions prior to version 5 only support 40 bit encryption. 128 bit encryption is more secure than 40 bit encryption.
User Password	If supplied, then this password must be entered for the document to be opened. Applications like Acrobat Reader will prompt the user to enter this password prior to displaying the document. Longer passwords are more secure than shorter ones - up to a maximum size of 32 characters.
Owner Password	If supplied, this password will have to be entered for users to change document Permissions. Permissions can be changed in programs such as Adobe Acrobat.
Permissions	These control what access the user has to the document. NB. If no owner password is present then these permissions can be changed by anyone who can open the document (if they have the appropriate software). Beware; there are programs available that can remove these permissions from PDF documents without the need of an owner password.