What method is used to verify firmware or software updates to prevent tampering?

• A. Password verification
• B. Checksums
• C. Physical security
• D. Cryptographic signatures

Answer: (D)

Verifying firmware or software updates to prevent tampering relies on cryptographic signatures. By signing the update with a trusted private key and then checking that signature with a public key (often via a certificate), the device can confirm two things: the update came from a trusted source and it hasn't been altered in transit. If the signature doesn’t verify, the update is rejected, stopping tampered or spoofed software from being installed.

Checksums can detect accidental corruption, but they don’t prove who created the update or protect against a malicious, signed-forged version. Password verification is about authenticating a user, not validating the integrity or origin of the code. Physical security helps prevent tampering with the device hardware, but it doesn’t provide a mechanism to verify the authenticity of the software update itself. Cryptographic signatures provide that trusted verification.