 |
|
|||||||
 |
||||||||
|
||||||||
The PDF specification states that the method used for encryption is the RSA RC4 algorithm at 40 bit key strength.
This is only partially true.
It is true that only 40 bits are used to generate the key to unlock the user password, but internally, each object is stored at 80 bit strength.
At activePDF, since we are dedicated to Windows solutions only, we decided to utilize the Windows CryptoAPI for generating our keys and encrypting/decrypting documents. The reason for this is threefold :
-
Microsoft has already licensed the RC4 algorithm RSA Security and as an owner of the Windows OS, you are entitled to use that API on your computers.
-
We are reasonably assured that the CryptoAPI will have the latest RSA routines embedded in it
-
Effective Jan 15, 2000, the CryptoAPI with strong encryption can now be exported world-wide with few exceptions.
How do you know if you have Strong Encryption?
Using RegEdit, navigate to the following key :
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Defaults\Provider
If you see a subkey called "Microsoft Enhanced Cryptographic Provider v1.0" then you have strong encryption installed.
How do you get Strong Encryption if you don't have it installed?
As we stated above, strong encryption can be exported in several Microsoft products with few exceptions.
If you are running Microsoft Windows 95/98/NT and have Microsoft Internet Explorer installed on your machine, you can get strong encryption by clicking on the following hyperlink :
http://www.microsoft.com/windows/ie/downloads/recommended/128bit/default.asp
If you are running Windows 2000, you can get strong encryption by clicking on the following hyperlink :
http://www.microsoft.com/windows2000/downloads/recommended/encryption/default.asp
If you do not fall into either of these categories, you can still get strong encryption by installing one of the products listed on the following hyperlink :
http://www.microsoft.com/exporting/
 |
 |
