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Re: What's the diff ?
Srinu,
>with respect to draft-ietf-ipsec-esp-v2-04.txt
>
>>From section 2.3
>
>o For some IV-based modes of operation, the receiver treats the IV as the
>start of the ciphertext, feeding it into the algorithm directly. In these
>modes, alignment of the start of the (real) ciphertext is not an issue at
>the receiver.
>
>*Can any one tell me what is the difference between (real) ciphertext and
>ciphertext. Because the ESP draft some times uses (real) ciphertext and
>some time just ciphertext. What's the difference between them?
>
>[Does the ciphertext means whole encrypted part of the packet and (real)
>ciphertext means just encrypted payload data]
We used the term "real ciphertext" to refer to the result of encrypting
plaintext, vs. the IV that may be prepended to this output. I think we may
have used the more generic term "ciphertext" to refer to the combination of
the two. I am not aware of generally accepted terms that address this
subtle difference between these two portions of the output from an
algorithm that makes use of an explicit IV, so we just adopted this
convention. The alternative would be to keep referring to the possibly
present IV, which makes for very awkward reading.
Steve
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