🔒 Full Name·ID Number → only SHA-256 hash stored on server
📱 Address·Phone stored on device only (not sent to server)
📧 Email → stored as plain text (name/address remain protected)
🔑 Full Name+주민번호로 iHash 재생성 → 서버 대조
📱 Address·Phone Number는 이 기기에서 자동 불러옴