Master the CHFI Challenge 2026: Crack the Code and Become a Cyber Sleuth!

The Electronic Serial Number (ESN) is indeed a unique identifier that is recorded on the secure chip in a mobile phone. The secure chip, often referred to as a trusted platform module or a secure element, is responsible for various security functions and storing critical information, including the ESN. This identifier is used by mobile networks to recognize devices and to authenticate them on the network.

Options concerning the SIM card, motherboard, or software within the device do not accurately reflect where the ESN is stored. The SIM card encapsulates other identifiers like the International Mobile Subscriber Identity (IMSI) and may also have some secure functions; however, the ESN is specifically tied to the device's secure chip. The motherboard hosts hardware components but does not directly store the ESN, and software embedded in the device typically relates to operating functions rather than hardware identifiers like the ESN. Thus, the relationship between the ESN and the secure chip clarifies why stating that it is recorded there is accurate.