>> For this reason signers SHOULD NOT reuse selectors with new keys, and >> SHOULD assign a new selector to each new signing key. > > > In other words, you want the Informative note to become Normative. > > Does the additional normative language make the protocol work better or add a > protocol feature? I tend to expect one of those benefits from normative > text.
I think it makes the protocol work better, by removing a possible failure mode in which the signature is good, but the validation key changed between the time a message was signed and it was checked. Although it would be rather dimwitted to do so, a signer with a severe fear of replay could keep the same selector and change the keys under it, or maybe rotate between two selectors with new keys each time. R's, John _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
