CompTIA CASP+ Practice Test

How should a system fulfill a need for generating unpredictable numbers for a Java-based application?

1. By storing all generated numbers

2. By using a simple algorithm

3. By implementing pseudo-random number generation

4. By leveraging a secure hash function

The correct answer is: By implementing pseudo-random number generation

A Java-based application requires a method for generating unpredictable numbers, which is crucial for scenarios like cryptography, gaming, or simulations where randomness is key. The most effective way to achieve this is through implementing pseudo-random number generation. Pseudo-random number generators (PRNGs) use algorithms to produce sequences of numbers that only appear random. While they are not truly random, they can provide a high degree of unpredictability, especially when the seed value (the initial input for the algorithm) is unpredictable. Java has built-in libraries, such as `java.util.Random` and `java.security.SecureRandom`, that allow developers to generate random numbers in a way that fits their application needs. This approach strikes a balance between performance and the level of randomness needed for most applications. In many cases, such as simulations or non-critical security applications, PRNGs suffice and perform well. Using a simple algorithm or storing all generated numbers would not meet the need for unpredictability, as they could lead to patterns, predictability, or even issues with memory efficiency. Leveraging a secure hash function, while it does provide some randomness, is not primarily designed for generating random numbers and would not be applicable for generating a sequence of unpredictable values efficiently.