I've not looked at the CryptoAPI or .net one, so I stand to be corrected...
But my understanding of DES was that it uses a 52bit key, but it was passed as a 64bit value including parity. 3DES would then use either 112 or 168 bit key, but these could be passed as 128 or 192 values including parity. I think the parity bits worked by setting the most significant bit of every byte to 1 of there is an odd number 1's in the 'real' 7 bits of the key, otherwise it's set to zero. Can't remember whether this is big or little endian though! The parity bits don't affect the result. So to convert between the keys you will need to either add or remove the parity bits. Hope this makes sense. -----Original Message----- From: dotnet discussion [mailto:[EMAIL PROTECTED]]On Behalf Of Buksbaum, David Sent: 15 May 2002 15:16 To: [EMAIL PROTECTED] Subject: [DOTNET] 3DES Compatibility I have noticed that the docs for the CryptoAPI states key sizes for 3DES as 2-key (112 bit) and 3-key (168 bit), and the key sizes in .NET are 128 and 192. I am wondering how I can have a non-.NET app using the CryptoAPI exchanged encrypted data with a .NET app using 3DES. Thanks David Buksbaum This message is for the named person's use only. It may contain sensitive and private proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you are not the intended recipient, please im mediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. CREDIT SUISSE GROUP and each legal entity in the CREDIT SUISSE FIRST BOSTON or CREDIT SUISSE ASSET MANAGEMENT business units of CREDIT SUISSE FIRST BOSTON reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorized to state them to be the views of any such entity. Unless otherwise stated, any pricing information given in this message is indicative only, is subject to change and does not constitute an offer to deal at any price quoted. Any reference to the terms of executed transactions should be treated as prelim inary only and subject to our formal written confirmation. You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. ***************************************************************************** The contents of this email and any attachments are confidential. It is intended for the named recipient(s) only. If you have received this email in error please notify the system manager or the sender immediately and do not disclose the contents to any one or make copies. ** eSafe scanned this email for viruses, vandals and malicious content ** ***************************************************************************** You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
