Flash memory apparatus for physical unclonable function and embodying method of the same

A flash memory apparatus having a physical unclonable function (PUF), comprising:

• a flash memory unit that comprises a main memory area and a peripheral memory area;
• a challenge input unit that receives input of a challenge value;
• a read voltage setting unit that sets a read voltage based on the input challenge value;
• a data reading unit that reads data by applying the read voltage to a memory cell included in the peripheral memory area based on the challenge value each time the challenge value is input;
• and
• a response output unit that outputs the read data as a response value corresponding to the challenge value;
• wherein the data reading unit reads at least one of a first data value based on setting data regarding an operation environment of the flash memory unit and a second value stored randomly in a pre-set memory area in the peripheral memory area, the pre-set memory area includes a plurality of memory cells comprising two or more memory cells having different threshold voltage values;
• and
• wherein the read voltage is changeable within a pre-set voltage level range each time the challenge value is input.