Patent ID: 7757092

Claim:
A data output apparatus comprising: a controller capable of performing operations of: receiving data to be output; storing the received data to be output in a data storing means; outputting the received data to be output from the data storing means; encrypting the received data to be output; storing the encrypted data in the data storing means; generating a decryption key for decrypting the encrypted data; storing the generated decryption key in decryption key storing means; transmitting the decryption key to an identification card which is carried by a manager of the data output apparatus and in which identification information identifying the manager is stored, and storing the decryption key in the identification card; determining whether or not the identification information transmitted from the identification card is received; decrypting the encrypted data using the decryption key stored in the decryption key storing means and permitting output processing based on the decrypted data, until a predetermined time has elasped since it was determined that the identification information was received; deleting the decryption key stored in the decryption key storing means when the predetermined time has elapsed; determining whether or not the decryption key transmitted with the identification information is received from the identification card after the decryption key is deleted; storing the decryption key received from the identification card in the decryption key storing means; decrypting the encrypted data using the decryption key stored in the decryption key storing means and permitting output processing based on the decrypted data, until a predetermined time has elapsed since the decryption key was stored; and deleting the decryption key received from the identification card when the predetermined time has elapsed.