There are even 3D businesses, which can replace a locksmith. They scan and save a copy of your key in the cloud. If you lose your key you only have to print a copy in an automat or any 3D printer. US company Keyme and Keysave from Belgium are two of the pioneers.
Keyme and Keysave scan the key from every angle with a 3D scanner. When PC för Alla tested the idea, we used a common picture, like the ones people might publish on Facebook.
It took a bit of work in 3D software to convert the photo to the kind of 3D picture needed for a successful 3D print. 3D software is usually quite advanced and takes experience to master, though the basics can be learned fairly fast.
"Most people can do it in 10-20 hours," says Anton Månsson.
A weekend of intense studying is enough, and you can teach yourself, at home on your own computer.
"There are plenty of free courses and 3D software online," he says.
Since the cost of the plastic used is negligible, you can afford to test things out.
That it may take several attempts to succeed becomes obvious when we copied our key. The first prints failed, and we had to make more until the key fit. To create the key isn't really difficult; the problem is to get the cuts and grooves in the right places, and that failed in our first attempts. For an experienced burglar this problem might not be such a huge obstacle.
The 3D technology is a huge challenge for the lock industry, even if it hasn't been a big problem in reality -- at least not so far.
"I don't know any cases where criminals have been using 3D printers," says Håkan Hedlund at SSF, the Swedish Theft Prevention Association.
His advice for those worrying is to take care of your keys and use a high-security lock.
The key we managed to print is a common door key, like the ones many of us use. It's fairly simple, and has a form that makes it possible to copy.
Other keys are harder to copy. High security keys have different grooves and depressions on each side to make them harder to copy.
Additionally, digital alternatives are being developed. Instead of a physical key you can, for example, open your door with a plastic card or your smartphone.
The problem is that even that kind of technology has been possible to hack.
"No matter what kind of lock you use, it's equally important to be careful and think about how you use your key," emphasizes Håkan Hedlund.
One person who had to think about all this was Christina Eberhardson. She was delighted when she was about to move into a new home in Stockholm and when she got the keys she took a picture of them and put it up on Facebook.
Sign up for CIO Asia eNewsletters.