Patent ID: 7178040

Claim:
A portable device usable with a plurality of different service providers including an integrated circuit for storing memory area division data and first area management key data, wherein the portable device is authorized to perform at least one of a write operation to a memory area of said integrated circuit and a rewrite operation to the memory area provided that the first area management key data requires a second service provider to provide a second service using part of said memory area of said integrated circuit when said portable device is issued by a first service provider providing a first service using said memory area, wherein the portable device includes a memory area operation unit for managing the key memory area division data, wherein the memory area operation unit encrypts first module data including second area management key data by the key memory area division data, and provides the same to the first service provider, wherein the first service provider encrypts second module data including the encrypted first module data by using said first area management key data and provides the same to the memory area operation unit, and wherein the memory area operation unit controls, providing the encrypted second module data to the integrated circuit, decrypting the second module data by using the first area management key data in the integrated circuit, decrypting the first module data in the decrypted second module data by using the key memory area division data, and dividing the memory area to a first memory area to be used for the services of the first service provider and a second memory area to be used for the services of the second service provider by using the second area management key data obtained from the decryption of the data.