Master the 2026 CRISC Challenge – Grab Your Risk Control Superpowers!

The correct choice reflects the proper mathematical formula for determining the number of unique key pairs needed when each user needs to communicate securely with every other user. In a cryptographic context, if there are N users, each user must establish a distinct key pair with every other user to ensure privacy and security in their communications.

The formula N * (N - 1) / 2 is derived from combinatorial mathematics, specifically the concept of combinations. This formula calculates the number of unique pairs that can be formed from a set of N elements by considering that each pair consists of two users, and since the order of users does not matter (i.e., pairing user A with user B is identical to pairing user B with user A), we divide by 2 to account for this symmetry.

Understanding this formula is crucial in the context of risk and information systems control, as it enables practitioners to assess the scalability and complexity of encryption systems when the number of users increases. It highlights the exponential growth of the need for key pairs as more users are introduced, which in turn impacts the system's overhead and security management strategies. Thus, using this formula helps organizations plan and allocate resources effectively in their information security frameworks.