Stephane, I agree that OE has been used in several different ways, and I suggest that in fact there are several different forms. It is likely the case that no one form will fit all uses. As such, it's a good opportunity for an informational document. In fact, I've suggested to several people that they take this on.
Eliot On 11/19/13 10:33 AM, Stephane Bortzmeyer wrote: > [Long quiet time on this list, time to resume discussions.] > > In draft-cooper-ietf-privacy-requirements-01, I find: > > "Opportunistic encryption" is defined as encryption without any pre- > arrangement specific to the pair of systems involved (e.g., by using > a Diffie-Hellman exchange). See [RFC4322]. > > I find this definition confusing (specially the reference to DH) > because it does not match the rest of the text which says: > > Where both opportunistic and one-sided or mutually > authenticated encryption are specified, protocols MUST also protect > against downgrade attacks so that scenarios where authentication is > required cannot easily be manipulated into using opportunistic > encryption which will often be subject to man-in-the-middle > attacks. > > The second paragraph seems to use OE as meaning "encryption without > authentication" (which is indeed vulnerable to man-in-the-middle > attacks). This is also how "opportunistic" is used in RFC 5386. > > The first paragraph (and RFC 4322) have a different meaning, OE being > "encryption without peer-specific setup" (and therefore being > authenticated, and not vulnerable to man-in-the-middle attacks). > > The discussions in Vancouver were very confused as well. Everyone was > talking about OE but with a different definition in mind. I strongly > suggest that we need either to have one definition and to stick with > it (the current draft is self-contradictory). Or to give in and to > stop using the term OE, poorly defined, and too loaded. > > Do not that Wikipedia has a third definition of OE (encryption with a > fallback to an unencrypted > mode) http://en.wikipedia.org/wiki/Opportunistic_encryption > > > > _______________________________________________ > ietf-privacy mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/ietf-privacy > > _______________________________________________ ietf-privacy mailing list [email protected] https://www.ietf.org/mailman/listinfo/ietf-privacy
