As some have rightly identified already, the key to understanding the potential threat to civil liberties posed by the Identity Cards Bill is not the cards themselves or even their content, the biometric data on which so much debate has focussed but rather on the database to which as this information will ultimately be linked, the National Identity Register.

With the publication of the bill its now possible to analyse fully just what this register will contain and why this might pose such a threat to our most important freedoms.

The key to understanding the Bill is, in actual fact, not contained within its main text but in a schedule to the Bill which defines the nature and extent of the information which may be stored on the register.

Much of what is specified here is already common knowledge to those with an interest in the subject and, for the most part, obvious even to the layman, which includes:

Full name – and any other names you’ve been known by
Date and place of birth
Gender
Your current address and any other addresses at which you may live for part of the year – and this is cumulative, so over time will form a complete record of everywhere you’ve ever lived.

Then there’s the somewhat more controversial identifying information which for the time being includes:

A photograph
Signature
Fingerprints, and
Other, as yet unspecified biometric information although, at least at this stage, the definition of biometric data as concerning only external characteristics, included for the purpose of the Interpretation Act 1978, would appear to rule out the inclusion of DNA profiles for the time being – although that’s not quite the impediment it might first appear, as you’ll soon see.

Oh and lets not forget that it will also record your nationality and, where relevant, immigrations status.

All of that, however, pales into insignificance when set against the provisions of clause 4 of the schedule, wherein lies the dark heart of the register.

To understand this section fully you need to understand a concept from the world of relational databases – relax, I’ll try not to allow this to get too geeky – and the concept of foreign keys. In simple terms a foreign key, in the context of the Register, is a piece of information stored in one database which enables you to identify information stored in another database.

If this seems difficult then the Bill provides a perfect example of what I mean – one of the many foreign keys that will be stored in the register with your new ID number is your National Insurance number. And once you have that number then you have the key needed to identify your tax and national insurance records as well as records of any welfare benefits you claim. You NI number is the key to several government databases, all of which hold information about you.

What of it, you might think? Well look a little more closely as you’ll find that your NI number is not the only foreign key that’s going to find its way into the register – just the ones that the Government have chosen to name explicitly include the serial number of your driver’s licence, passport number and, if you’re not a UK citizen, any immigration documents that relate to you and your stay in the UK.

Ok, so far, so good…

… But hang on a second, what about all the other governmental records systems which could also provide keys to be stored in the register?

Well that’s covered, but in a very interesting and extremely disingenuous way. You see having named a few obvious candidate foreign keys, what the government does next is drop into the Bill a rather clever little catch-all clause which states that in addition it can also add to the register – without your consent, btw:

“The number of any designated document which is held by the applicant that is a document the number of which does not fall within any of the preceding sub-paragraphs”

A designated document? What’s that?

Well, basically any official document issued under the provisions of an Act of Parliament which contains a unique identifier which could be used as a foreign key in the register.

Now just think about that for a second.

Any official document – in other words any set of personal records held either the government, an agency of the government or an agency working for the government. That’s your council tax records, police records, court records, social services records, medical records, military service records [if you’ve been in the armed forces] and potentially even your personnel and employment records [if you’ve ever been employed in certain types of work in the public sector].

The National Identity Register is far more than just a record of your identity, its also the skeleton key the government needs to unlock and connect together records of almost every aspect of your life.

Oh, and I should mention, that’s why the exclusion of DNA profiles from the register is not quite as reassuring as it might at first seem. You see the government doesn’t need to include such information in either the ID cards themselves or the register. All it, in fact, needs to do to add DNA profile information is add another foreign key to the register to enable it to link to a DNA database held elsewhere.

What’s most interesting, and revealing of the Government’s attitude to debate on identity cards and the register, in not the information it explicitly tells you its going to store, but all the information it will store without ever telling you what it intends to do – all the records covered by the catch-all clause, even where there may be some very good arguments in favour of identity registration in some cases.

Your NHS medical card number is a perfect illustration of this issue.

From the standpoint of a clinician, and especially medical staff working in A&E departments, in particular, the Identity Register and its link to the new computerised NHS medical records system could be massively beneficial – a real lifesaver in fact.

Each year literally thousands of people will be admitted to A&E departments across the UK needing emergency treatment in circumstances in which medical staff have no idea of exactly who they are and the patient is unable to identify themselves – just think of someone walking home on their own who ends up in road traffic accident as an example. In such situations medical staff may quite literally be, flying blind, in trying to treat them. No identification, no medical records. No medical records, no way of knowing whether the treatment you plan to give them could actually kill them rather than cure them.

It should be obvious to anyone, even the most hardened opponent of ID cards, just what the benefits might be in that situation – take your John Doe, run his fingerprints through the biometric scanner and straight away, assuming the system works, you have their identity, and from there, their medical records and all of a sudden, as a doctor, you can be sure of the treatment they need.

Now you’d think, playing Devil’s Advocate here, that this would just the kind of scenario the Government would be desperate to push as more justification of the positive benefits of introducing ID cards. How much more persuasive argument could their possibly be than ‘your ID card could, one day, save your life’.

So why is this not part of the debate? Why, indeed, is there no mention whatsoever of including your NHS number on the register? Quite simply, because people have a very different attitude to their medical records than they do to things like their tax and national insurance records and the government knows this very well.

Its a question of differing perceptions.

Your tax records may be personal to you in the sense that they relate specifically to you but, on the whole, people don’t see those records as things which belong to them on a personal level. They’re not just your records but they legitimately belong, also, to the Government – after all, without them how would the government collect its taxes.

Medical records are a very different matter. Most people seen those as being very personal, in fact just about as personal as it gets. People trust and believe in, implicitly, that the Doctor-Patient relationship is and should remain entirely private, after all you’ll often tell your doctor things you wouldn’t even tell your family, let alone the government. Despite the fact that your medical records are actually held by a government agency, the NHS, people possess a very clear sense of who those records should and shouldn’t be disclosed to and the list of shouldn’ts certainly includes the government itself.

In reality, there’s nothing in the ID cards bill, itself, which suggests that it will allow the government, the police or anyone else to intrude on the privileged relationship we have with doctors, for the simple reason that that relationship is covered by an entirely different Act of Parliament.

Nevertheless, in terms of public perception, the idea that the National Identity Register will include a key which could be used to access your medical records would make a lot of people very anxious indeed – while many people may instinctively support the idea of ID cards and the register when its use is linked to issues such as combating fraud, identity theft and illegal immigration, they’re likely to be far less certain that its a good idea when faced with the possibility that it could give the DSS a means of accessing their medical records as part of a drive against benefit fraud, especially at a time where we have a government committed to getting people of incapacity benefit and into work by any and every means at its disposal.

This issue of foreign keys and the ability it may give government agencies to accurately cross-link different source of information has certainly been recognised by those campaigning against the introduction of ID cards but what also seems clear is that they haven’t yet quite understood the full extent of what may, indeed what will be possible, as a result of the creation of a national identity register.

That’s not to say that they’ve got it wrong, merely that they’ve yet to understand the full scope of what is possible and that, as a result, their arguments aren’t as yet as fully formed as they could, and really should be.

But then that almost certainly explains the indecent haste with which the Government is pursuing these proposals – the longer the debate the closer people will get to understanding the full extent of what’s possible by using the register and the more likely it is that these proposals will lose much of the shine of public support they currently seem to attract.

UPDATE – 27/5/05

I’ve added an important update to this argument here – please read.