While it might not be the perfect solution for the truly invaluable items you own, a box you unlock with your own intellect is a surprisingly safe way to store your important belongings.
MAKE Magazine can show you how to make one. Creator Claudio Bernardini offers a little insight into this DIY contraption:
My architect friends Lorenzo Bini and Roberta Pezzulla made this little project for a very young and dynamic client: Lorenzo's 6-month-old goddaughter. They wanted to make a box that the child could use her whole life to store small, personal, precious things. So they created the UnaBox, taking inspiration from an Indian box (by an anonymous designer) that had an obscure opening system with 2 pivoting lids.
To create your own UnaBox, you'll need a few basic woodworking skills. It involves very simple construction and then only requires you learn how to open it. It's the sort of box that's easy to open if you know the process, but very puzzling if you don't. It's not a bad way to store a few important items safely, so long as you don't share the box's secret.
For the full instructions in many formats with plenty of pictures, be sure to check out the full post over at MAKE.
The UnaBox [MAKE Magazine]