(ISC)2 Certified in Cybersecurity Practice Exam

True or False: Hash Functions may fail if they are reversible or if they are not collision-resistant.

1. True

2. False

3. Depends on the implementation

4. Always True

The correct answer is: True

The statement is true because hash functions are designed with specific properties that are critical to their effectiveness in cybersecurity practices. A reliable hash function must be irreversible, meaning it should not be possible to reconstruct the original input data from its hash output. If a hash function were reversible, it would undermine its security utility, as attackers could potentially recover sensitive data. Moreover, a hash function must be collision-resistant, which means it should be challenging to find two distinct inputs that produce the same hash output. If a hash function is not collision-resistant, it can lead to security vulnerabilities, such as having different data produce the same hash, allowing for possible forgery or substitution attacks. Thus, if a hash function fails to be irreversible or collision-resistant, it does not fulfill its intended security role, making the statement true.