Sentence:  Before too long, secure public key cryptosystems will make routine personal communications 100% secure. You'll use E-mail and digital voice, but since it's easy, you'll use security all the time. Your key will probably be stored in a smartcard or <WSD>smartwatch</WSD> that you carry with you. ... Will they have to do lightning raids on people they suspect to grab their computers while they are still on with the keys in ram? Rip your <WSD>smartwatch</WSD> off your wrist to get your code? 
Meaning of the word marked with <WSD> tags:  A mobile device worn on the wrist with a touchscreen display.