#pdf encryption

PDF Password Remover is a small application to decrypt PDF files with the owner/master password. It can directly remove PDF restrictions on editing, copying, printing and more. And it can also use to delete PDF user/open password if you have the correct password.

Small yet efficient PDF security remover.

Remove PDF restrictions on editing, copying, printing, etc.

Delete an open password from an…

Note:This article is quoted from lianjump.livejournal.com  At the very first, I want to you know that this is an elusive article giving you a basic understanding of PDF encryption type.

PDF encryption is vital to secure confidential and important content in PDF files. Users apply encryption to encrypt a PDF just as you lock doors of your house to prevent others’ unauthorized access unless you deliver the permissions.

There are so many tools out there allow you to encrypt PDF files under RC4 or AES. But what are RC4 and AES?

General speaking, Both RC4 and AES are encryption type.

RC4 (also called ARC4 or ARCFOUR): In cryptography, RC4 is the most widely used software steam cipher and is used in popular protocols such as Secure Sockets layer (also known as SSL) and WEP.

RC4 was created by RSA Security in 1987. RC4 generates a random stream of bits (a key stream). As with any stream cipher, these can be used for encryption by combining it with the plaintext using bit-wise exclusive-or; decryption is performed the same way (since exclusive-or is a symmetric operation).

KSA (The key-scheduling algorithm)

The key-scheduling algorithm is used to initialize the permutation in the array “S.” “keylength” is defined as the number of bytes in the key and can be in the range 1 ≤ keylength ≤ 256, typically between 5 and 16, corresponding to a key length of 40 – 128 bits. First, the array “S” is initialized to the identity permutation. S is then processed for 256 iterations in a similar way to the main PRGA, but also mixes in bytes of the key at the same time.

AES (Advanced Encryption Standard)

Advanced Encryption Standard (AES) is a specification for the encryption of electronic data. It has been adopted by the U.S. government and is now used worldwide. It supersedes DES. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data.

Finally, thank goodness, we let all these elusive stuff past. What we really concern is how could we decrypt there two different type of encryptions. Basically, there are two types of RC4 and one type of AES that are popular for PDF encryption. They are 40-bit RC4 encryption, 128-bit AES encryption and 128-bit AES encryption. Many user ask us “Does ** PDF Password Remover support 128-bit AES?”

The good news is all PDF password removers we collect support to crack these three encryptions.

Here is the list of products that displayed on our site:

Wondershare PDF Password Remover

Wondershare PDF Password Remover for Mac

Doremisoft PDF password Remover

Features

Decrypt PDF for editing (changing), printing, selecting text and graphics from PDF files.

Support Owner Password and User Password.

Do not need Adobe Acrobat installed in a computer.

No installation, no registration, its free and easy to use.

Platform independce. No matter which system you use now, Windows XP, Windows 7, Linux, Mac OS X, IOS or Android.