Telephone numbers – the original digital identity
This post has been stewing for some time, and perhaps the fuss today over the launch of the .tel domain gives me a good reason to serve it up.
It’s my view that telephone numbers were THE original digital identity scheme. Of course like most pioneering activities things weren’t thought through particularly well, and we’ve seen various changes and kludges applied along the way. The system still works though, and most people (even amongst the less technically savvy) are aware of the limitations without even giving them much thought.
Security seems like a good place to start. For some reason my colleagues in the IT security world seem to turn purple and start ranting when I talk about telephone numbers being a type of digital identity. “They’re not secure”, I hear the cry. Let’s put things into perspective – a number is just a type constrained special case of a string format address. Less constrained cases (that are also used for the purposes of digital identity) include email addresses and OpenID URIs. None of these things are inherently secure or insecure, but we tend to associate them with the various degrees of badness embedded in the common implementations. When I dial a number I could be misdirected elsewhere (by an attacker, or just some clever call forwarding), and when I receive a call with caller line identification (CLI) it could be spoofed. It is true that the telephony system that we mostly use today is riddled with security hole, and that there are few good ways of establishing trust, but that’s mostly not the fault of the numbers.
Namespace management has been a key problem over the years. As the use of telephone numbers for personal identity became more common we see the same growing pains that we’re presently encountering in the journey from IPv4 to IPv6. Corporate exchanges were a bit like NAT, but corporate citizens came to demand personal addresses (=numbers), and sometimes more than one (for fax machines etc.). We also bump up against some cognitive psychology issues here – too much namespace = too long to remember. For those of you with kids you can think of yourself as being an expensive NAT router next time you answer their calls :)
Geographic anchoring is somewhat related to the namespace management issues. This is of course a hang over from the days where the physical location of exchange switching equipment was meaningful, but it continues to affect us. I’ve been trying for some time to run with ‘one number’ – a single telephone number that will reach me wherever I am in the world, on whatever device I choose to have with me. The mechanics behind this work surprisingly well; all of the issues are around social etiquette that’s annealed around our use of numbers. People still get offended when I don’t give them a ‘mobile’ number, and others find it impossible to grasp that dialling something that’s purportedly anchored in London will actually reach me in office in NY (or wherever else). I’m told that in some parts of the world great significance is attached to which class of number (from many on a business card) should be used at any given time.
Of course ‘one number’ isn’t a panacea. People still worry about things like long distance costs and roaming charges. +44 may alienate those from +1 or +34 or whatever (it may even be blocked on some corporate exchanges and pay as you go mobiles); so what I may really need is some identity virtualisation, and luckily services to do this already exist.
So, rounding up, telephone numbers were there being digital identity before the term was even coined. Since we still use telephones a lot we still have to consider the use of telephone numbers as part of a broader identity landscape, and that’s particularly important when the conversation moves onto unified communications – something that I’ll probably post about another day.
PS I’m intrigued by the utility of putting contact data into DNS versus something webby like Portable Contacts, and would love to hear stories of how this will be used in anger?
Filed under: identity | 5 Comments
Tags: .tel, digital identity, identity, numbers, portable contacts, telephone