Patent ID: 7552324

Claim:
A The printer which processes print data, comprising: a printer position information acquisition unit which acquires printer position information to specify a place where the printer is installed; a first printer position information acquisition unit which acquires printer position information from the printer position information acquisition unit, this printer position information being regarded as first printer position information; a public key generator which generates a public key with a passphrase containing at least the first printer position information and a given number; a print data receiver which receives print data encrypted with the public key; a second printer position information acquisition unit which acquires printer position information from the printer position information acquisition unit when the print data has been received, this printer position information being regarded as second printer position information; a private key generator which generates a private key with a passphrase containing at least the second printer position information and the given number; a decrypter which decrypts the print data received by the print data receiver with the private key; a print executor which executes a print operation based on the print data when the print data has been decrypted with the private key and which does not execute the print operation based on the print data when the print data has not been decrypted with the private key; and a given number holder which holds the given number used in the public key generator, wherein even if a private key is generated when the public key generator generates the public key, the private key is deleted.