The Hilton hotel chain is about to test using NFC-equipped smartphones as door keys, with a trial about to start in 10 of its UK properties -- and an ambition of getting around 100 wired up for it by the end of the year. It's not some sort of cutting-edge new thing it's just come up with, though, as the chain's digital key system is already in operation in about 1,700 hotels in the US and Canada, where security concerns about the use of the keyless option have failed to result in any bad things happening during the 11m uses of the app and activation tool. Hilton's Geraldine Calpin says the firm has hired security teams and hackers to test whether it's really unhackable, with the company not recording any breaches thus far. Which sounds like a challenge to the UK hacking scene is about to go live. Get the full story at 9to5Mac