FOI request (FOIR-798100789)

Under the Freedom of Information Act 2000, please provide the following recorded information held by your department regarding assurance processes for software based data erasure of end of life IT equipment.

For clarity, this request relates solely to software based data destruction. Please exclude physical destruction methods such as shredding, crushing, degaussing or disintegration.

1.      Please confirm whether departmental policy, contractual terms or internal procedures require an explicit outcome based warranty or guarantee confirming that personal data has been rendered irretrievable through software based erasure, whether carried out internally or by an external provider.

2.      Where software based data destruction is performed internally, what recorded evidential assurance does the department rely upon to conclude that the final data state is irretrievable?

3.      Where software based data destruction is performed by a third party provider, does the department hold recorded information demonstrating that any warranty or assurance provided explicitly extends to the software erasure method used and its claimed effectiveness? If so, please confirm the recorded nature of that verification.

4.      Where no explicit outcome based warranty is required or provided, what recorded form of evidential assurance does the department rely upon to conclude that software based erasure has rendered personal data irretrievable?

I am not requesting technical configuration detail, security sensitive information or supplier specific vulnerabilities. I am seeking confirmation of the assurance model relied upon for software based data destruction.

Notice of Refusal

Disclosure of information relating to ICT systems, infrastructure and security constitutes a security risk as it would leave the Council's computer assets more vulnerable to a malicious hacking attack. This means that disclosure would:

• Make the Council more vulnerable to crime (Section 31)

• Risk harming the systems on which the day-to-day business of the Council relies (Section 43)

Section 31 (Law Enforcement) Section 31(1)(a) states that information is exempt if its disclosure is likely to prejudice the prevention or detection of crime. ICO guidance states that this can be used to protect information on a public authority's systems which would make it more vulnerable to crime. This exemption can be used by a public authority that has no law enforcement function:

• To protect the work of one that does

• To withhold information that would make anyone, including the public authority itself, more vulnerable to crime

The crime in question would be a malicious attack on the Council's computer systems. Since the disclosure of the withheld information would make the Council's systems more vulnerable to such crime, the exemption is engaged.

The exemption is subject to the public interest test.

There is an overwhelming public interest in keeping the Council's computer systems secure which would be served by non-disclosure.

This outweighs the public interest in accountability and transparency that would be served by disclosure.

Section 43 (Commercial Interests) Section 43(2) states that information is exempt if its disclosure would, or would be likely to, prejudice the commercial interests of any person (including the public authority holding it). Disclosure of information relating to ICT systems, infrastructure and security puts the council at risk of a malicious hacking attack. This would compromise the Council's ability to provide its services and carry out 'business-as-usual' should our systems be compromised. Were our systems to be compromise, the cost of a system recovery would be detrimental to the Council's commercial interests.

The exemption is subject to the public interest test.

There is an overwhelming public interest in keeping the Council's computer systems secure which would be served by non-disclosure.

This outweighs the public interest in accountability and transparency that would be served by disclosure.