Wednesday, June 01, 2005

Art thou a SAML'ite?

Notwithstanding its most recent manifestation, a shibboleth is a word or phrase that can be used to distinguish one group of speakers from another, typically through pronunciation. In the Bible, the Gileads used the fact that the dialect of the people of Ephraim did not include the 'sh' sound. Consequently, when an Ephraimite was challenged to say 'Shibboleth', it came out as 'sibboleth'. The Ephraimite was thereby identified and quickly slain (slewed, smite ?).

In World War II, the Finnish underground took advantage of the complete unpronounceability of their language (e.g. Nokia) to ferret out infiltrators. Our Canadian border officers now use the pronunication of 'out and about' in a similar manner.

Shibboleths are not always used in such a prejudicial and divisive manner. By identifying differences they can serve as focus point for dialog and self-improvement. For instance, Americans pronounce the last letter of the English alphabet 'zee', the entire rest of the world, as was intended, says 'zed'. Throughout history, many awkward situations have been defused because of this humourous distinction.

In this spirit of the word, e.g. acting to bring people together through self-awareness of their differences, I propose here a shibboleth for distinguishing the SAML community from other federated identity management initiatives, namely the term 'back-channel'.

For SAML'ites, the term refers to a SOAP-message channel between providers, distinguished from a browser-intermediated 'front-channel'. Other federated identity proposals either have no corresponding channel in their architectures or, if present, do not describe it in this manner.

Other, less technical, interpretations for "back-channel" are also possible and thereby make 'back-channel' an option for the desired shibboleth between the tribe of SAML and others. If you are unable to say/write 'back-channel' without your mind straying to such alternative interpretations, then you cannot be of the SAML tribe.

With increased awareness of this fundamental differentiator amongst its members, the federated identity community can now move forward and tackle the more significant issues that confront us. As my analysts like to say, the first step to getting better is admitting you have a problem.

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