A lockbox is a small hardened container with a strong lock to prevent unauthorized folks from opening it and viewing what is inside.
It became one of Al Gore's unintentional catchphrases during the presidential election between him and George W. Bush, enough that Gore was lampooned by Saturday Night Live.
There are many styles and versions of lockboxes, but the one most folks are familiar with are the small black lunchbox-sized containers that people use to make change at lawn sales or by convention vendors. I've used them for years selling my books at conventions, and it can also hold extra pens, a credit card dongle like the one for Square, and a small receipt pad for keeping track of sales for tax purposes. The other form many folks are familiar with are the fire insulated boxes where folks keep their important documents in case the house burns down.
Iron Noder 2017