One of the best features of PDF files is the password protection which can be usually set with any PDF editor. Some ebooks in PDF format adds more security by preventing users from doing copy, edit and print. The latest version of PDF uses 256 bits AES encryption, which is comparatively difficult to unlock. However, if the character length is less, there are some methods to recover passwords from older PDF versions. Here we have few utilities to unlock protected PDF documents to copy, edit and print them.
Two online services Ensode and Unlock-PDF allow users to upload PDF files to their server and unlock them online. Converted PDF files can be edited as per user interest. First service let you to upload PDF file up to 5 MB in size, and will be opened in a new browser window after conversion. The second one has both free and premium PDF unlocking facilities, from which the later offers more advanced features for new and complex PDF encryptions.
2. Unlock PDF files and remove copy, edit and print restrictions using freeware PDF-crack (PDF1.6, Acrobat 7.0) .
PDF crack is a freeware PDF unlock tool for Windows and Linux. Though there is no GUI, the command line interface is well written to be used.
Download PDF crack and extract files. Run the command line utility and provide the directory of target PDF file. If you know the password length, the process can be accelerated by providing the maximum and the minimum values.
Download PDF crack.
The same author has another freeware utility PDFcrypt, intended for decrypting protected PDF files. It supports PDF files of standard 48 bits, 128 bits, AES-128 bit encryption.
3. Remove copy, edit and print restrictions from PDF using freeware PDF unlocker.
Download freeware PDF unlocker and just drop the target file to the application icon. Unlocked and non-password protected PDF file will then be produced instantly.
Download freeware PDF unlocker.
Screenshot capture software can easily produce image screenshots of PDF file, which later can be converted using Optical Character Recognition software (OCR). PDF Files are digital documents, so we can expect exactly similar outputs by using a good OCR application.
There are a large number of shareware apps available for advanced unlocking of PDF files. Some of them offers demo versions too.
Note: These utilities are meant for unlocking non-copy protected and legal PDF files.
Update: Here is promotional offer to download free license code for AnyBizSoft PDF Password Remover