Final answer:
The easiest authentication strategy to compromise is reliance on user knowledge, such as passwords or security questions, as it can be obtained through social engineering or breaches.
Step-by-step explanation:
The easiest authentication strategy to compromise or crack is d) reliance on user knowledge. This method often involves something the user knows, such as a password, PIN, or answers to personal security questions.
In comparison to biometrics like iris configuration, fingerprint analysis, or voice pattern recognition, which require physical or behavioral traits unique to the individual, user knowledge can be easier to obtain through social engineering, guessing, or through data breaches where such information is often stored.
For example, passwords can often be guessed if they are simple or common, and answers to security questions can sometimes be researched or guessed based on publicly available information. Biometric methods, on the other hand, typically require specialized hardware to breach, making them more secure and less likely to be compromised.