Warning: this is part four of what is intended to be a nine-part blog looking and expanding on what identity is!
If you have arrived here directly, then please go back and start at part 1 - after all, in the Identity world context is everything! [sorry for the identity in-joke].
Part Four - Making risk-based decisions based on understanding attributes in context
This is the start of the “how do we make it all work” part - and again the problem is, that how we make it work in the real world needs to be totally different from the band-aid “kludges” we cobble together in the computer world; And then we wonder why we can’t make it work, or leverage it everywhere.
So, let’s look at a real-world example of making a risk-based decision. For those that don’t know me, one of my “personas” is that of a white-water kayak instructor, with both Scouting and a local junior Kayaking club.
So, let’s look at what we would call the “entitlement” criteria if I were to offer to take your (precious) 13-year-old on the (London 2012 Olympic) white water course at Lee Valley just outside London.
Of course, in the “good old days” we would just have said “he’s a really good chap, and everyone says he knows what he’s doing”; but that was before 1993, when an outdoor activity centre killed four teenagers, (see: Wiki: “Lyme Bay canoeing disaster”); so in the UK we need to be properly licensed with risk-assessments in place.
Thus, I need to be able to offer a number of attributes, all from their authoritative sources, as a set, immutably linked to me (with a known level of certainty).
- Proof I’m over 18, thus legally responsible
- A current British Canoeing, Level 3 (or better) Kayak Coach qualification
- A current scouting kayaking permit
- A UK enhanced DBS Check (proof that I’m not prohibited from working with children)
- A Lee Valley user card (proving I’ve passed their test to be able to use the course)
As you can see, each is from a different authoritative source, and that last thing those organisations want to do is maintain attributes for which they are not authoritative, because non-authoritative attributes go stale, and are near impossible to maintain; (and because if there was an accident and an inquest and it turns out that my taking them was based on their incorrect / unmaintained information then they could be liable).
Thus, the other lesson that can be drawn from this example, is that the “entitlement” check should be carried out in real time (or as near real-time as possible) using current attributes.
In addition, as the coach, I need to do a series of risk-assessments;
- It's an outdoor course, what’s the weather like?
- Each participant's personal capability, are they up to it?
- Do we have the correct safety equipment and processes in place if there is an issue.
- Have I been briefed by Lee Valley staff on any current issues / changes / new processes.
- Dynamic risk: e.g., We start to get freezing hail, do we end the session (hypothermia risk) etc.
Of course, as humans we do variations of that risk assessment continuously and mostly subconsciously, from crossing the street, to walking down a dark alley at night, meeting new people, or deciding to take a new job.
So, this leads us to a series of “principles” on how to process attributes in context, resulting in a risk outcome that meets the risk-appetite of the entity taking the risk; remembering that risk is bidirectional but asymmetric.
As the consumer of the attribute(s)
- Risk is temporal, and WILL change over time, thus must be re-evaluated in line with your risk-appetite.
- Attributes must be consumed in the full knowledge of the entity that signed them. (Remembering that some attributes could be self-asserted).
- Attributes must be consumed in the full knowledge of the entity that is presenting them, and level of immutability between presentee and the attribute they are asserting.
- When multiple attributes, from potentially disparate personas, are asserted, then you must have an acceptable level of proof that all the attributes are linked to that single entity.
- Only request attributes required to support your risk calculation, or meet a legal obligation (such as KYC).
As the intermediary
- (Never turn a variable into a binary) always pass on the attribute, and the provenance of the attribute, so the entity taking the risk can evaluate the whole picture.
As the issuer/signer of the attribute(s)
- Only hold, maintain and sign attributes for which you are truly authoritative.
As the presenter of the attributes
- (Where possible) only present attributes in a privacy enhancing manner (“I am over 18” rather than “Date-of-Birth”).
- Understand why attributes are being requested, and reject requests/transactions that over demand attributes.
Two final thoughts
The evaluation of risk is not just about evaluating the asserted attributes; it also needs to factor in as much supporting information as possible.
Maintaining groups of attributes in a “persona” that is tied to the authoritative source has major security advantages; as all they are doing is maintaining their attributes, thus if they are breached, or their signing key is compromised, then they need to re-issue the key and attributes at their cost. However, as they hold/maintain no others, nothing else is affected.
In part five, I will look at why privacy needs to be at the heart of any identity ecosystem.
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