Ex-barrister reckons he has a privacy-preserving solution to Britain's smut ban plans

Interview A British firm says it has developed a tech proposal for preventing children from watching unsuitable internet videos – and doing so without needing age verification or other privacy-busting features.

SafeCast Global, run by Alistair Kelman, reckons it has the solution to the age-verification kerfuffle that threatened to create, in the UK, a register of every adult wishing to watch pornography in their own time and on their own devices.

Although the previous Conservative government under Theresa May shelved its porn ban plans in its dying days in October 2019, they came perilously close to fruition. The data store necessary to enforce such a ban would have been a severe intrusion into people's privacy and a giant floating target for hackers, both of the blackmailing variety and the state-backed sort, making using the internet in Britain an extremely dangerous activity for sensible people.

Against this backdrop, one-time criminal barrister Kelman's proposals are, if not perfect, certainly eye-catching. At its heart they seem deceptively straightforward as SafeCast Global's website describes: instead of age verification, content creators (YouTubers, smut pedlars, broadcast TV companies, and so on) place an encoded marker or tag in the video file.

This, argues Kelman, could be done by tweaking the existing TSP 2121 standard for TV video files to require the inclusion of so-called "HeadCodes". TVs, phones, set-top boxes and the like could then be updated to read those codes and play or refuse to play associated content.

"By inserting the SafeCast HeadCode labels within the TSP 2121 standard, it will be possible to enable filtering of content to protect children. This involves amending just one field in the definitions in TSP 2121 to include a SafeCast HeadCode," the company's website explains.

Kelman himself told The Register: "If our proposal is accepted, the content is labelled by the creator so it's easy to filter out inappropriate content from young children, using the lightweight filter. That's not censorship; adults can view the content in the unfiltered state." SafeCast's plans do appear to rely on consumer equipment and middleware being able to read the HeadCodes and block the playing of age-inappropriate content, which in turn implies the implementation of parental control mode.

SafeCast's chief added that the firm is "mapping this onto the National Curriculum" so age-appropriate content could be graded in bands rather than requiring the viewer's precise age in order for content to be filtered out or included.

"Children need to be protected," he told The Register, explaining his inspiration for the scheme lay in the early 2000s when he left the criminal bar and began working in countering child abuse imagery: "I had never encountered this field before. I was so horrified by what was actually out there, the way people were behaving, that was what drove me into coming up with these ideas."

There's one seemingly obvious flaw with the content labelling plan on the face of it, though: what if a content creator or uploader doesn't want to play ball with the SafeCast HeadCode labelling system?

"First of all, on the engines as it comes up there may well be some AI that supports you," said Kelman. "So that when you're labelling it, right, this content is a '4' on a graduated scale. The system comes back at you and says, 'is it a "4"? Really?' You can override that and put it on. But the moment you put it out there your reputation is at stake. If you don't want to label it yourself, what we anticipate is that you'll be able to ask for what we call a Safecheck labeller to put the correct label on your content."

Intriguingly, SafeCast Global isn't planning to charge for this technology, as Kelman told El Reg: "We've created this, we have the trademark for Safecheck, but it's not our core business, its something we want to to give away free. For lots of people over the world this could be an employment opportunity – and boy oh boy, do we need employment opportunities right now!"

Kelman also said his proposals had received some pushback from Google, which, he said, perceived it as a potential rival to Safesearch filtering technology on the adtech firm's search engine. The difference, he said, is that SafeCast's HeadCode system would operate on a transparent basis.

While the scheme may not be perfect, and is a stepping stone for further discussion, the very idea that a privacy-compliant content labelling and filtering programme is technically feasible may help privacy advocates and others who don't want to find themselves on state-mandated databases when – not if – the porn ban plan rears its ugly head again. ®