Forum Discussion
Is it possible to crack PDF password?
I recently encountered a similar problem. I forgot the password of an important PDF file. I was really anxious. I tried many methods on the Internet, but none of them worked. Later, I found a tool called iSeePasword Dr.PDF, which is very easy to use. It only took 2 hours and it actually recovered my 6-digit password without affecting the file content.
I recommend it to you! I hope it can help you!
https://www.engadgot.com/how-to-recover-pdf-password
MaryDoe PDF password protection can use two primary types of security: user passwords (for opening the document) and owner passwords (for permissions like editing, printing, etc.). The encryption techniques used in PDF files have evolved over time. This leads to different hash types depending on the PDF version and the encryption algorithm used.
RC4 (40-bit/128-bit) Encryption: PDF versions 1.0 - 1.7 (before Acrobat 6.0). 40-bit encryption is considered very weak by today's standards and can be cracked with brute force within minutes to hours. This means it is easy to crack PDF password from old PDF files.
AES (128-bit/256-bit) Encryption: PDF versions 1.6+ (Acrobat 7.0+). AES-128-bit can be cracked with significant computational effort but is considered secure for the time being.
Even with strong encryption, the password length and complexity are crucial factors. A short or simple password (e.g., "12345" or "password") can make even AES-256 encrypted PDFs vulnerable to brute force or dictionary attacks by using a dedicated PDF password cracker software.