217
The Age-Checked Internet Has Arrived
(www.wired.com)
This is a most excellent place for technology news and articles.
In theory, it isn't hard to make it work, give everybody born on the same day a specific UUID and use that to authenticate with a database if it is true or false. Store the ID somewhere where the person has access to (ID/Passport/Digital passport etc) and it should be enough. Get IT persons and accountants to regularly audit it for security and if they keep logs/don't have UUID's per person etc.
But that's not how it seems to work for the UK at this time