UK web snoop charter: Just how much extra info do spooks need?

How to make DPI fly

Returning to the ISC's report, the committee took evidence from BAE-owned Detica, which provided information about Deep Packet Inspection (DPI) probes that could be used in cases where CSPs had declined to allow spooks to access communications data and the government made the decision not to take civil action against those providers.

Detica, which supplies DPI to the government, described the technology as "flexible" and told the committee that it was regularly used for commercial purposes.

But the committee noted that the Home Office had "a presentational issue to address in terms of the amount of DPI that may be used, what companies it may be targeted against, and how soon UK network CSPs may be asked to use it."

CSPs are said to be nervous about creating frosty relationships with overseas companies if DPI were used to extract communications data from those outfits not willing to cooperate. They only want DPI to be used as a "last resort", the report found.

It said:

We are... sympathetic to their argument that the Home Office should have to demonstrate due diligence before resorting to the use of Deep Packet Inspection to collect communications data from overseas Communications Service Providers, and we recommend that this should be reflected on the face of the Bill.

The ISC also touched on websites and online services moving to encrypt their pages with the HTTPS protocol, saying that the government has "[redacted] options in dealing with the challenge encryption poses." Further information about that method was also kept secret.

Critics have suggested that encryption would render DPI pointless.

The notion of developing a "filtering tool" to bring together fragmented communications data from any number of CSPs was also looked at by the committee, which apparently failed to consider such a collection eventually morphing into a central database for police and spooks that might possibly be managed by Detica.

It concluded:

The ISC considers that a filtering mechanism would offer considerable benefits to the Agencies. It would save many hours of analysis, and reduce the amount of collateral intrusion from complex communications data requests.

The technology seems to exist to provide this. It will be a significant challenge to integrate the numerous data sets from different Communications Service Providers to make the filter work, as well as to manage the expectations of the various departmental and Agency stakeholders. The record of government in managing such complex IT projects is mixed at best.

The ISC report broadly welcomed May's draft bill as it reads today, but with some important caveats.

More thought is needed, the committee concluded, in relation to the order-making power laid out in the draft bill to help convince Parliament and the public that the legislation is necessary.

It called for more consultation with CSPs and a better, more detailed explanation of how communications data would be used and what safeguards might be put in place.

Behind the scenes, the Home Office is understood to be busy with a rewrite. This comes after Deputy Prime Minister Nick Clegg said the government had to go "back to the drawing board" because some of the proposals were considered unpalatable in their current form.

As for the much-contended costs floated by the Home Office, a source close to the situation has suggested to El Reg that the CCDP price tag could hit close to £5bn over the course of 20 years if the legislative overhaul does take flight. ®