AUTHENTICATION CIRCUIT, SEMICONDUCTOR ELEMENT AND METHOD OF USING THE SAME, IC CARD AND METHOD OF USING THE SAME

摘要

PPROBLEM TO BE SOLVED: To provide an authentication circuit, etc., preventing information from being decoded in the non-destructive state, capable of writing or deleting information after the manufacture, and suitable for various devices for preventing forgery. PSOLUTION: The authentication circuit has at least two types of ferroelectrics with different Curie temperatures among ferroelectrics exhibiting charge holding characteristic by the remnant polarization. When the temperature is held at least at the Curie temperature of one ferroelectric and lower than the Curie temperature of the other ferroelectric, the authentication signal stored in the one ferroelectric is deleted. Preferable modes of the circuit are: a mode when the one ferroelectric can output a primary authentication signal and can output a secondary authentication signal when the other ferroelectric inputs the primary authentication signal, a mode when the (n) type of ferroelectric consists of at least two kinds of elements, and the composition of the elements is different for each ferroelectric, and the two kinds of elements are selected from among the group of Na, K, Ba, Cd, Hf, O, Pb, Zr, Ti, La, Ca, Sr, Tl, Bi, rare earth elements, Nb, Ta, W, Mo, Fe, Co and Cr. PCOPYRIGHT: (C)2003,JPO