Friday, 21 February 2014

The Security of the Proposed Scheme


Ceri the Duck has a blog post titled "Care.Data – why I am happy for my medical records to be shared for research". In this post, they make the argument that under the scheme, data protection would be improved for patients.

In this post, I will tackle this misconception, which revolves around two core arguments; firstly that there will be limited access to identifiable information, and that the scheme will provide a better security framework to work within.

No Identifiable Information

" will only provide access to ‘potentially identifiable’ information"
If we look at the HSCIC price list, we see that they provide an extract of data "containing personal confidential data".

Even if this data has names, and other directly identifiable data stripped out, we know that anonymised data can be de-anonymised almost trivially (Further reading from Light Blue Touchpaper) in the vast majority of cases.

A Better Security Framework

"I am much happier with the level of data security will provide than with the current ad-hoc arrangements. They will be consistent, with good oversight, the information disclosed will only be what is needed instead of having to comb through a patient’s full record, ..."
This is simply not true. The scheme will be taking medical records from a setting where they are hard to even sort through with legitimate access (as pointed out by the author themselves) to a situation where the records will be much more easily accessible to many thousands of people, none of whom will have undergone any serious training into information security, data protection laws, or the ethical issues surrounding the use and dispersal of this data. It is also highly unlikely that they will have had so much as a criminal record background check.

Granted, the current situation is very poor, but it does not allow for a large scale abuse of the system. Sure, I could target Bob Smith, break into his doctor's surgery and steal his record. With the new system, I could target large swathes of the population by simply bribing the right people. The information gained could be used by all manner of people, be it for surreptitious back ground checks on potential dates, to discrediting a political candidate, and everything in between.

And that's just bribing-based attacks. Think of the rubber hose cryptanalysis opportunities, the social engineering based attacks, physical security attacks, phishing and spear phishing attacks, attacks on end-point security (this is your classical "hacking into the computer" attack), and so on.

Data transfer must occur at some point, and with great data transfer comes great opportunity. How do you conduct the transfer of data, and how do you setup the transfer so that you're definitely sending the data to the person(s) you think you are? These are generally considered to be solved problems in the cryptographic community for the most part (key distribution is hard, for instance), but in practice, it is anything but.

In short, this centralisation effectively paints a massive target on the back of the country's medical records, and gives access to institutions with some of the worst information security going in many places.

The adversaries in this situation will not be small time. Computer crime is big business, and aside from nation states, organised criminals are one of the hardest adversaries to defend against. They are extremely well organised and well funded, with extensive experience attacking high value targets. Once they've breached the system, they have the contacts in to sell the data on and actually turn a profit on this kind of attack.


Security is far harder than most people think, and most people don't know how much they don't know. HSCIC cannot be in the position of implementing this system and not be aware of the serious and numberous risks outlined.

The scheme will suffer a breach, and given how centralised the system is likely to be, I expect the breach to be a large and very serious breach of previously unheard proportions.

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