Hello, Everyone.

I am evaluating the TDES (prj name : des).

On the Tripple DES's CBC Mode, Initial Vector(IV) is needed.
But I couldn't find that in rtl code.

Plz, describe that.

Thks for reading!

The IV is not there. I have also evaluated the TDES and found it is more accurately called "CBC-capable". I mean the area-optimized option is usable for CBC application, but the CBC logic is not included. The speed-optimized option is not usable for a CBC implementation due to the pipelining. However, you can easily add CBC capability outside of the core provided. For encryption: 1) Exor the IV with your first block of plaintext before encrypting 2) Exor each subsequent block of plaintext with the block of cipertext generated in the previous step. For decryption: 1) After decrypting the first block of ciphertext, exor the resulting plaintext with the IV. 2) After decrypting each subsequent block of ciphertext, exor the resulting plaintext with ciphertext from the previous block. This can't even be attempted with the speed-optimized version, because subsequent blocks are started before the previous block has completed. That is why I think it is more accurate to call the area-optimized version "CBC-capable" I found Bruce Schneier's "Applied Cryptography" real helpful for figuring these things out. Best regards, Allan ----- Original Message ----- From: gwkim007 at nate.comgwkim007 at n...> To: Date: Mon Mar 31 07:23:39 CEST 2008 Subject: [oc] TDES's Initial Value(IV)