Patent ID: 8433069

Claim:
A software defined radio device, comprising: a storage unit for storing an identification code of the software defined radio device itself and a plurality of common keys for encrypting data and performing mutual communications with a communication entity, said plurality of common keys being commonly held by this software defined radio device and the communication entity; a download initiation unit for sending data to the communication entity; a common key identification unit for identifying one common key from the plurality of common keys based on data received from the communication entity which received the data; a verification unit for encrypting the data sent to the communication entity with a common key identified by the common key identification unit and calculating a hash value with a hash function from the encrypted data; a download request unit for encrypting data including the identification code with the common key identified by the common key identification unit and sending the encrypted data to the communication entity in the case where a hash value calculated by the verification unit matches a hash value included in data received from the communication entity; a decryption unit for decrypting download data received from the communication entity with the common key identified by the common key identification unit; a confirmation unit for calculating a hash value with a hash function from download data decrypted by the decryption unit in the case where an identification code included in the decrypted download data matches the identification code stored by the storage unit; and a modification unit for using software data included in the decrypted download data to modify a communication function in the case where a hash value included in the decrypted download data matches a hash value calculated by the confirmation unit.