Hi phil,

While "Protecting" code space in a pic does make it more difficult for someone to get your data out of it. It's not invulnerable. With enough determination and a bit of money, everything in the chip can be retrieved.

With that in mind, if they can get the data, they can get the encryption key or decryption key, whichever is available. So really, encrypting something on the chip won't really do much for you.

Where it will be of good use is encrypting data that will be sent out or in via RS232 or through a network, or anywhere that someone could intercept the data.

Another use might be to encrypt data that is in an external EEPROM. Those can be read very easily.

Best regards,
   Darrel