Semiconductor integrated circuit on IC card protected against tampering
AssigneeFujitsu Limited
InventorShunsuke Fueki
Life of this patent
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Abstract
A semiconductor integrated circuit includes a memory which stores secret data, a bus which is connected to the memory and transfers an encrypted address and encrypted data, a processing unit which encrypts what is to be transmitted to the bus based on an encryption key, and decrypts what is received from the bus based on the encryption key, thereby accessing the memory, an encryption/decryption circuit which is situated between the bus and the memory, and which decrypts what is received from the bus based on the encryption key and encrypts what is transmitted to the bus based on the encryption key when the processing unit accesses the memory, and an updating circuit which performs a process for updating the encryption key at predetermined intervals.
Claims10
A semiconductor integrated circuit, comprising:
- a memory which stores secret data;
- a bus which is connected to said memory and transfers an encrypted address and encrypted data;
- a processing unit which encrypts what is to be transmitted to said bus based on an encryption key, and decrypts what is received from said bus based on the encryption key, thereby accessing said memory;
- an encryption/decryption circuit which is situated between said bus and said memory, and which decrypts what is received from said bus based on the encryption key and encrypts what is transmitted to said bus based on the encryption key when said processing unit accesses said memory;
- and
- an updating circuit which performs a process for updating the encryption key at predetermined intervals.
A method of protecting security of an IC card;
- comprising the steps of:
- encrypting, based on an encryption key, a signal of secret data and a signal of an address of the secret data which are transferred on a bus;
- and
- updating the encryption key at predetermined intervals.
Dependencies are inferred from the claim text.