A personal digital security device needs to be even stronger than an ATM card to protect PCs and network security. ATMs are trusted devices, but PCs have many security flaws requiring a stronger key than what a standard magnetic stripe ATM card can offer. Network security devices use smart card technology. This is a small computer with its own software in a credit card-sized plastic card or USB token. If it is a card, it has a gold contact on it. You either insert this into a smart card-ready keyboard or laptop, or into a reader. USB devices work like Flash drives, just plug it into a USB connector.