Patent ID: 6075862
Filing Date: 2000-06-13
Classification: G06F

Abstract:
A method for managing a decryption key for decrypting an encrypted software to be installed into a computer using a software distribution system in which the decryption key is obtained in exchange for a payment of a software usage charge, and the encrypted software is obtained without the payment of the software usage charge, comprising the steps of:searching the decryption key in a memory device of said computer, the memory device including a software content memory unit for storing a software content of each currently installed software and a decryption key memory unit for storing each decryption key for decrypting each previously installed and subsequently deleted software;acquiring the decryption key from a distribution source of the encrypted software in exchange for the payment of the software usage charge when the decryption key is not found in the memory device by the searching step;decrypting the encrypted software by using the decryption key obtained at the searching step or the acquiring step, installing a decrypted software content of the encrypted software into the software content memory unit of the memory device, and storing the decryption key into the software content memory unit of the memory device; anddeleting the encrypted software by deleting the decrypted software content installed at the decrypting step and the decryption key stored at the decrypting step from the software content memory unit of the memory device, and storing the decryption key into the decryption key memory unit of the memory device, such that the decryption key stored in the decryption key memory unit of the memory device is utilizable in decrypting the encrypted software at a time of re-installing the encrypted software without requiring another payment of the software usage charge.