METHOD OF COUNTERING SIDE-CHANNEL ATTACKS ON ELLIPTIC CURVE CRYPTOSYSTEM

A method of countering side-channel attacks on an elliptic curve cryptosystem (ECC) is provided. The method comprises extending a definition field of an elliptic curve of the ECC to an extension ring in a first field; generating a temporary ciphertext in the extension ring and countering attacks on the ECC; and generating a final ciphertext for the first field if a fault injection attack on the ECC is not detected. The countering of attacks on the ECC may comprise countering a power attack on the ECC. Checking if there is a fault injection attack on the ECC may be performed by determining if the temporary ciphertext satisfies a second elliptic curve equation. The fault detection algorithms takes place in a small subring of the extension ring, not in the original field, to minimize the computational overhead. The method can improve the stability of the ECC and reduce computational overhead of the ECC.