I'm working on a .net app that is going to send a request to an existing Java servlet that is expecting a string in a DES encrypted form.  I've been comparing code samples from various sources that do DES encryption in vb.net against the ones written in Java.  The code samples written in Java do not seem to have a variable called "IV" (initialization vector) or "salt".  Is there a way to get vb.net to work like the Java samples?  I've tried using an empty byte array or setting it to nothing, but I'm not getting the response I expect.

 Thanks

Hi

Initialization vectors (IVs) is a continuously changing number used in combination with a secret key to encrypt data, which prevent dictionary attacks. For example, without an initialization vector, "password" will always encrypt to the same thing, and which makes a dictionary attack easier.

The initialization vector is not used with ECB mode but is important for other usage modes such as CBC. So I think you'd hava a look at your java code and give more information about this.

For further detailed information please refer to:

http://tcllib.sourceforge.net/doc/des.html 

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Thanks for your response.  ECB was exactly what we needed.  It seems that a lot of the samples going around the internet are wrong also, the byte array length is incorrect on them.  Here is the final code that works: 

1    	Public Function EncryptToBase64String(ByVal stringToEncrypt As String, ByVal SEncryptionKey As String) As String
2    		Try
3    			'convert our input string to a byte array
4    			Dim inputByteArray() As Byte = StrToByteArray(stringToEncrypt)
5    			'convert the key to a byte array
6    			key = StrToByteArray(SEncryptionKey)
7    			'now encrypt the bytearray 
8    			Dim des As New DESCryptoServiceProvider
9    			des.Mode = CipherMode.ECB
10   			des.Key = key
11   			Dim ms As New MemoryStream
12   			Dim cs As New CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write)
13   			cs.Write(inputByteArray, 0, inputByteArray.Length - 1)
14   			cs.FlushFinalBlock()
15   			' now return the byte array as a "safe for XMLDOM" Base64 String
16   			Return Convert.ToBase64String(ms.ToArray())
17   		Catch e As Exception
18   			Return e.Message
19   		End Try
20   	End Function

although ur post is so old. em also suffring from the same problem.have to add a java applete and have to pass DES ENCRYPTION values.i saw ur post and tried.in ur this function KEY varibale was not defined.i also have to have 'StrToByteArray' function. as i open the page and called this function on button click to verify results. i provided it the 32 character key (which was being supplied to encrypt string in java) and a simple string link to convert.  it throughs exeption specified key is not a valid size for this algorithym... 

wot is the iv how can i create or get iv for my 32 character key???

i urgently req help on this... em pasting my code below

Inherits System.Web.UI.Page

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

End Sub

Public Function EncryptToBase64String(ByVal stringToEncrypt As String, ByVal SEncryptionKey As String) As String

Try

'convert our input string to a byte array

'convert the key to a byte array

'now encrypt the bytearray

' now return the byte array as a "safe for XMLDOM" Base64 String

Catch e As Exception

End Try

End Function

Dim encoding As New System.Text.UTF8Encoding

End Function 'StrToByteArray

End Class