A user support system for cryptographic communication includes a key storage
for
storing keys used for deciphering, a deciphering part for deciphering an enciphered
communication text into a deciphered communication text using a key, and a controller
for starting the deciphering part only when an input communication text is the
enciphered communication text and for supplying the key that is necessary for the
deciphering in the deciphering part by retrieving the key from the key storage.
