NHS email encryption

[PeteM]

Ian G Batten wrote:
> 
>>
>> past medical history, drug history and
>>> allergies is plenty to identify most people down to single figures,
>>
>> These items cannot be used to identify a subject - i.e. discover his 
>> name and address - because each particular (named) individual's drug 
>> history is not in the public domain, unlike his age, sex, address etc.
>>
> 
> I'd take evens on someone who knows how to read a set of records being 
> able to identify an individual given a drug history, a postcode and 
> electoral roll information for the residents of that postcode.  For 
> women, I'd take 2/1 on: the drug history's going to identify the pattern 
> of children they've had.
> 

Perhaps, but the drug history is useless without the full postcode. What 
you're showing is what a dangerous piece of information the postcode is 
when used in inference attacks.

There are only 36 addresses that match my postcode, and at an average 
occupancy of 3 that narrows it down to only 100 people. So it's an even 
more specific identifier than my *name* (there must be thousands of 
Peter Mitchells in the UK). In areas that are less densely populated 
than SW London there are probably even fewer households per postcode.

If researchers are to be given full postcodes - which I doubt - we will 
want to know the reason why.

-- 
Pete Mitchell