METHOD OF ENCRYPTING AND DECRYPTING THE DATA OF THE SESSION STATE

The present invention discloses a method for conveniently and safely encrypting and decrypting session state data stayed in a volatile memory such as a register or a random access memory (RAM) during encryption with a software encryption product for protecting data in a computer. The disclosed encryption method encrypts the session state data based on a calculated counter value and a predetermined key by calculating the counter value corresponding to the session state data based on a session extinction counter value for a password session and an identity of the password session corresponding to the session state data. The disclosed decryption method reads the session state data for decryption from a memory and decrypts the session state data based on the calculated counter value and the predetermined key after calculating the counter value based on the session extinction counter value for the password session and the identity of the password session corresponding to the session state data. The present invention enhances difficulty for hacking encryption session state secret data stayed in the volatile memory during the execution of a program because the session state data stayed in the volatile memory can be safely stored. Therefore, the safety of the secret data such as authentication data and a key of data protection products of a software type executed in a computer is improved. [Reference numerals] (10) Session ID = i state data; (14) Session ID = operation mode counter Ni session extinction counter Pi session flag Fi; (16) Key; (18) Encryptor; (20) Session ID = i encrypted state data; (AA,DD) Session ID = 1; (BB,EE) Session ID = 2; (CC) Session ID = n encrypted state data; (FF) Session ID = n counter Pn flag Fn