Chip-level security for IoT devices is achieved by implementing security measures directly into the hardware, such as secure boot, secure firmware updates, and device authentication. This involves storing cryptographic keys in a tamper-resistant environment within the chip, ensuring that sensitive information remains secure even in the event of physical attacks on the device. Closing insecure network services is part of a broader security strategy that includes chip-level measures to protect against cyberattacks. It’s important to note that while changing passwords and encrypting interfaces are also security measures, they do not pertain specifically to chip-level security.

References: The information provided is based on industry best practices and insights from sources such as EE Times1 and Semiconductor Digest2, which discuss the importance of establishing a root of trust and securing IoT devices from chip to cloud. These sources emphasize the need for a focus on endpoint devices and the implementation of security mechanisms and techniques depending on their specific function and security requirements. Additionally, they highlight the role of public key infrastructure (PKI) in providing strong identities for IoT devices, which is a critical element of chip-level security.