AES is the new encryption standard being used in smart chips, cellphones, and database encryption. It's fast and secure, and expected to become more widely used in the following months. Unfortunately, .NET does not include AES in it's encryption library, so you will need to implement your own class.
The original idea for this class came from: http://msdn.microsoft.com/msdnmag/issues/03/11/AES. The author of this article had made a class available which does the actual AES encryption, however, the class wsa limited in what could be encrypted. I took the original class and modified it to allow the user to encrypt strings, to send a string password, and to encrypt blocks of data larger than 16 bytes.
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Ummm .NET DOES INCLUDE AES... AES is Rijndael, .NET has two namespaces, Rijndael and RijndaelManaged that you can do to use AES! (If this comment was disrespectful, please report it.)
No, you are not correct. AES is not Rijndael. They are sepeate algorithms for encryption. The MSDN article explains it like this: "In late 1999, the Rijndael (pronounced "rain doll") algorithm, created by researchers Joan Daemen and Vincent Rijmen, was selected by the NIST as the proposal that best met the design criteria of security, implementation efficiency, versatility, and simplicity. Although the terms AES and Rijndael are sometimes used interchangeably, they are distinct. AES is widely expected to become the de facto standard for encrypting all forms of electronic data including data used in commercial applications such as banking and financial transactions, telecommunications, and private and Federal information." (If this comment was disrespectful, please report it.)
3/17/2005 12:03:59 AM:
The difference between AES and Rijndael is that AES has a fixed block size of 128 bits and a key size of 128, 192, or 256 whereas Rijndael can be specified with key and block sizes in any multiple of 32 bits, with a minimum of 128 bits and a maximum of 256 bits. VB.net Rijndael has a Skip Size of 64 bits. Here is a few lines of code to get key sizes:
'create the Rijndael Crypto object Dim rmRijndael As New RijndaelManaged
Dim KS() As KeySizes KS = rmRijndael.LegalKeySizes()
MsgBox( (If this comment was disrespectful, please report it.)
3/17/2005 12:09:33 AM:
Dim rmRijndael As New RijndaelManaged Dim KS() As KeySizes KS = rmRijndael.LegalKeySizes() MsgBox("Minsize = " & KS(0).MinSize _ & Chr(13) & _ "Maxsize = " & KS(0).MaxSize _ & Chr(13) & _ "Skipsize = " & KS(0).SkipSize) (If this comment was disrespectful, please report it.)
3/22/2005 5:55:48 AM:
It will be great if the actual encrypt/ decrypt of a value can be shown by allowing inputs through a winform.. I tried this sample by initially converting it to VB.Net and then calling the instance of this class. I not getting as to how should i pass the values for encrypt/decrypt. The constructor initial accepts the (If this comment was disrespectful, please report it.)
3/22/2005 5:58:13 AM:
can u please show the encrypt/decrypt functionality in actual work? i tried this by putting 3 textboxes and passing the values to the instance but could not achieve the results (If this comment was disrespectful, please report it.)
there is an error encrypting/descypting string long a number of digit divisor of 16 (and long less then 16 digit). I resolved the problem simply putting this codeline in the function "GetArraySize" (first of all): if (Arraylen <= 8) ArrayLen = 16; (If this comment was disrespectful, please report it.)
I believe there is an problem when the length of the string to encrypt is evenly divisible by 16 AND is > 32 (e.g. 32, 48, 64, 80...). If you encrypt something like "0123456789abcdef01234567890abcedef" (32 bytes) it appends 16 extra zeros to the encrypted output which then decrypts incorrectly. The fix appears to be in GetArraySize. there is a line if ( (BlockSize % ArrayLen) == 0) which is trying to determine if the length of the data is evenly divisible by 16. The dividend and divisor are reversed. It should read if ((ArrayLen % BlockSize) == 0) (If this comment was disrespectful, please report it.)
In NetFrameWork 3.5: http://msdn2.microsoft.com/en-us/library/bb352381.aspx (If this comment was disrespectful, please report it.)
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2/24/2005 6:07:48 PM: 
