Provided is an information security apparatus that has enhanced stability and confidentiality of a hash key. The information security apparatus includes an information generating PUF unit that has tamper resistance set, using physical characteristics, so as to output a preset hash key, a partial error-correction information storage unit that stores partial error-correction information, an error correcting PUF unit that has tamper-resistance set, using physical characteristics, so as to output error-correcting PUF information, an error-correction information generating unit that generates error-correction information using partial correction information and the error-correcting PUF information, and an error correcting unit that corrects an error for the hash key outputted from the information generating PUF unit and outputs an error-corrected hash key.