Re: DES CBC Mode

Ocean wrote:

> Hi, I am implementing the encryption aspect of a transaction system at
> work and the customer sent me some encrypted data and the key that was
> used to encrypt this data. I am trying to unencrypt the data with
> "Cryptool" and it can't decrypt it.
>
> The question I have is, if they are always using the same IV (let's say
> 0), do they HAVE to add it to the encrypted data, or do I have to
> change my algorithm to always use the same IV?

"No", "it's XORed, not added", and "No".

Maybe the customer is testing to see whether you know
anything about cryptography.

-- 
Peter Pearson
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