Captain Midnight returns?

...put it on your crypto feature ring. Has a sort of futuristic ring to it.

Hmm, perhaps we should eventually build real Captain Midnight Decoder Rings, which would fit around your finger. When the face of the ring was inserted into a DIN-plug serial port, it would power up, and talk a serial protocol to do the crypto operations needed to sign and decrypt messages, a la Phil Karn's design. There are smart-card microcontrollers with most or all of the right features -- we'd just have to figure out how to pot one into a ring with a truncated DIN-plug. John