What does signed firmware guarantee before installation?

Signed firmware ensures integrity by validating the firmware before installation. This process involves using cryptographic signatures to verify that the firmware is from a trusted source and has not been tampered with since it was created. This validation is crucial, as it helps to maintain the security and functionality of the device by ensuring that only legitimate firmware updates are applied. When firmware is signed, the device can check the signature against known public keys, thus confirming that the firmware has not been altered in any way that could introduce vulnerabilities or instability.

The other options do not directly relate to the primary function of signed firmware. For instance, while improved camera zoom capabilities and additional security features might be benefits of certain firmware updates, they are not guarantees given by the signing process itself. Network bandwidth allocation is also unrelated to the concept of firmware signing, as it pertains more to network management rather than the integrity of firmware. The signing process specifically focuses on ensuring that the firmware is authentic and complete, providing a foundational level of security before any updates are performed.