PdfCrypt is too old, and should retire now, please visit qpdf (supports the newest AES-256 bit encryption and decryption) for a better alternative.
PdfCrypt is a windows 32 console/command line version PDF encrypt & decrypt software, supports standard 48 bits, 128 bits, AES-128 bits encryption, and decryption. And first of all,it is free.
- remove restrictions on any secured PDF document (you should have the right to do it, for example, if you forgot the password). Any Acrobat version up to 9 is supported, even with 128-bit AES or 128-bit RC4 encryption. PDF restrictions removal is an instant process. Unlocked file can be opened in any PDF viewer without any restrictions so you may edit/copy/print it.
- remove the PDF open password. Decryption of the file with password for opening is guaranteed for PDF files Any Acrobat version up to 9 is supported, even with 128-bit AES or 128-bit RC4 encryption,but you must know the password first.
It is free software, but if you like it and want to donate it, please select buy it to give us donation.
If you do not have windows system, or do not want to download a software and learn how to use, feel free to use PDF Password Remover Online