Free ISC2 CISSP Actual Exam Questions - Question 2 Discussion

Makes sense to rule out B and C since they don’t really relate to how plaintext changes impact ciphertext. A fits the idea of spreading out changes well. So I’d say A.

A, because diffusion is about spreading out the influence of each plaintext bit over many ciphertext bits. Permutation just shuffles bits around but doesn't ensure a small change in plaintext affects much of the ciphertext. Obfuscation and encapsulation don't directly relate to this principle. So diffusion fits perfectly here as it’s the classic property that makes sure a small plaintext change causes widespread ciphertext differences.

A/D? Diffusion definitely sounds right since it’s about spreading changes, but permutation in D only rearranges bits without ensuring widespread change. So A works better here.

A/D? Diffusion (A) is about spreading influence of plaintext bits, but permutation (D) rearranges bits, which can also help spread changes. Still, diffusion fits better for affecting many ciphertext parts.

It’s A for sure. Diffusion is all about mixing the plaintext bits so that flipping one bit changes lots of ciphertext bits. The other options don’t really fit—permutation just rearranges data, not necessarily spreading changes, and obfuscation or encapsulation are unrelated here.

Option A, diffusion ensures small plaintext changes impact whole ciphertext.

Probably A, diffusion’s about spreading changes through ciphertext.