Moving forward, NFC will now be offered on both the USB-A and USB-C keys, which means that most users will be able to streamline their keys down to a single unit. Must read: Best security keys: Protect your online accounts If you have an older system with USB-A ports, Google recommends that you buy a USB-A + NFC security key, which should work with most smartphones and tablets. This is the key recommended for iPad users who have a Lightning port on the iPad (they will also need an Apple Lightning adapter). If you have a more modern system that makes use of USB-C, then the key for you will be the USB-C + NFC security key. Bluetooth Titan Security Keys will continue to work, and warranties will continue to the honored by Google. The USB-A+NFC security key, which comes with a USB-A to USB-C adapter, costs $30, while the USB-C+NFC security key costs $35. Both are available from the Google Store. A good alternative to Google’s Titan security keys are the YubiKey line, and come in a wide variety of options.