Charles Duncan ...

^ A Radio Shack manager told me that the Radio Shack digital
^ scanner, $499.99, will decode any encrypted transmission.

You've been misinformed. A digital receiver will convert (decode) a digital
signal to expose the content, often analog audio. But if the content, perhaps
analog audio, has been encrypted, then you're left something useless to you.

This message will be encoded by my newsreader and encoded further by the
sockets interface, then it will be decoded by any computer receiving it. If I
were to encrypt this message before sending it, perhaps with PGP, it would
still be twice encoded and decoded and you would be left with an encrypted
message that is useless to you.

The receiver you refer to cannot decode all types of digital information and
it cannot decrypt anything.

Frank