A-PDF Password Security is a desktop utility program that lets you change password security of existing Acrobat PDF files. That means you can protect PDF files with 128 bit encryption, or remove existing password protection. It can handle either single or batch documents. Another convenient features include password pool and hot directory.

Why A-PDF Password Security
Encrypt PDF Files
Protect your PDF documents from unauthorized access with standard password security:
40-bit RC4 encryption, which is supported by Adobe Acrobat 3.0 or above.
128-bit RC4 encryption, which is supported by Adobe Acrobat Reader 5.0 or above.

Decrypt PDF Files
You can also remove the standard password security from protected PDF files. Supports 40/128 bit RC4 and 128 AES encryption.

Note: you may get a password prompt to open the file. If you have no idea what password is, the program can not find passwords automatically for you, you may find a PDF password cracker tool here.

Change Restrictions of PDF Files
With A-PDF Password Security, you can set a PDF file to require a password to open, and/or restrict access. For example, to allow or not allow printing, copying content, changing the file, etc.

Batch Change Properties of PDF Files
With A-PDF Password Security, you can batch edit and modify your PDFs metadata, such as PDF Title, Subject, Author and Keywords.

Add Expiry Time and Data to PDF Files
With A-PDF Password Security, you can set or remove expiration Time and Date on a PDF.

Password Pool
If you need unsecure a batch of PDF files with one password, you can special a password pool. A-PDF Password Security will try the passwords one by one, instead of input them manually.

Work with Hot Directories
You can set up a monitored directory, where all files written to that directory will be encrypted as they are saved. The original files can also be moved to a backup directory. All of the operations will be recorded in log files.

Home Page: http://www.a-pdf.com/security/password.htm