Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
- edechenLv 72 decades agoFavorite Answer
Advanced PDF Password RecoveryThis program (Advanced PDF Password Recovery, or simply APDFPR) can be used to
decrypt protected Adobe Acrobat PDF files, which have "owner" password set, preventing
the file from editing (changing), printing, selecting text and graphics (and copying
them into the Clipboard), or adding/changing annotations and form fields (in any
combination). Decryption is being done instantly. Decrypted
file can be opened in any PDF viewer (e.g. Adobe Acrobat Reader) without any
restrictions -- i.e. with edit/copy/print functions enabled.
The program is also able to convert Kinko's Document Format (KDF) files to PDF
files (without any protection).
Please note that APDFPR does not work with documents which have user-level
passwords (preventing the files from being opened), if both user and owner
passwords are unknown.
Professional edition also allows to search for "owner" and "user"
passwords with brute-force and dictionary attacks, effectively optimized for
speed (however, don't expect to recover long passwords in a resonable time
with these attacks). In addition, it has Key search attack, which
guarantees the decryption (regardless the password length and complexity)
of PDF files that use 40-bit encryption (the attack takes about 3-4 days
on modern dual-CPU systems).
Warning: APDFPR APDFPR Pro do NOT work on Mac computers with Virtual PC; unfortunately, it seems to be a problem of
Virtual PC itself. Also, PDF files protected with any 3rd party
security plug-ins such as FileOpen (FOPN_fLock) are not supported.