A method and apparatus of printing a document in a secure manner, includes receiving, by a printer, print data that has been encrypted using a printer public key. The printer-public-key-encrypted print data is decrypted by the printer using a printer secret key, to obtain decrypted print data as well as user identification information provided with the print data. Print pre-processing is performed by the printer on the decrypted print data, to thereby obtain pre-processed print data. The pre-processed print data is encrypted by the printer using a user secret key to obtain user-public-key-encrypted print data, and the user-public-key-encrypted print data is stored. The user-public-key-encrypted print data is decrypted and printed by the printer upon receipt of a user secret key, prior to printing the print data.