No proof of purchase needed and no decoder ring in the box.

However, fuzzy memories established the idea of "secret decoder rings," so some were developed.

We'll start by going back to our decoder ring.

"This is what I get for leaving my decoder ring at home!"

For the decoder ring, the algorithm tells you to move a certain number of letters.

You've just got to have the magic decoder ring with this guy.

This event is enough to burn out anyone's cultural decoder ring.

Now, the tiny chip has given us an electronic-age decoder ring.

This is no simple decoder ring, and it will probably not be of much use to the average E-mail user who wants privacy.

- space, most of which would benefit from being processed through a decoder ring.