ANPR Capabilities

Dear Sir or Madam,

I read with interest your recent response to a freedom of
information request to Mr Francocci. In your response dated 20th
February 2009 you state:

"We do not record full number plates - they are converted into a
tag through a non-reversible encryption process. The same number
plate will produce the same tag and this enables journey times to
be judged and anonymity to be maintained."

I would like to know more about this process. What is the exact
'non-reversible encryption process'? Is is a cryptographic hash? Is
the whole number plate encrypted? Any document--or an index of
documents--that details this process would be appreciated.

You also state:

"We do not provide the police with the data gathered routinely but
do help them with specific investigations."

Please tell me what the nature of this assistance is.

Further, could you please confirm that data from the ANPR cameras
are kept within the Highways Agency and that the maintenance,
analysis, the storage of ANPR data, is not contracted to an
external body.

Yours faithfully,

HMP Britain

Dear Sir or Madam,

Please pass this on to the person who conducts Freedom of
Information reviews.

I am writing to request an internal review of Highways Agency's
handling of my FOI request 'ANPR Capabilities'.

A full history of my FOI request and all correspondence is
available on the Internet at this address:
http://www.whatdotheyknow.com/request/an...

There are a few areas in my original email that I feel have not
been addressed by the response. I have briefly summarised these
below and are in the order they appear in your original FOIA
response:

1. I requested information on 6th September, not 6th December
stated in your letter.

2. Contains contradictory paragraphs each with the words '[Delete
where appropriate]'. I assume these have been left in error.

3. I requested 'more information about [the process of hashing]'. I
expected this to include but not be limited to the exact hashing
algorithm.

4. In relation to point 3, I requested any document or index of
documents that details the process of hashing. This has not been
provided.

5. On the point of helping police with enquiries, I fail to see
how--if this data is classed as non-personal data and hashed
appropriately--that you would be able to help the police with their
enquiries. I am keen to hear how you are able to help the police in
a meaningful capacity and eager to hear more. An index of documents
is fine.

5. You give the impression in your response that the VRN data is
hashed at the camera site into a non-unique tag and sent to the
National Traffic Control Centre and then to Traffic Information
Services. Could you please confirm these are the only recipients of
the tags, and that this data--with a different hashing algorithm or
without one at all--is not also sent somewhere.

Yours faithfully,

HMP Britain

Dear Mr Allen,

Many thanks for your timely response to my request for an internal
review.

I find myself dissatisfied with the outcome of your review and will
take the matter up with the ICO.

Yours sincerely,

HMP Britain