A smart card looks like a credit card and stores your digital ID on an embedded microprocessor chip. You can use the digital ID on a smart card to sign and decrypt documents on devices that include a smart card reader.

Similarly, a security hardware token is a small, keychain-sized device that you can use to store digital IDs and authentication data. You can access your digital ID by connecting the token to a USB port on your computer or mobile device. The token may include a keypad that lets you type a personal identification number (PIN).

If you store your digital ID on a smart card or hardware token, you must specify that information when you sign or certify documents.