Explain why design conflicts might arise when designing an architecture for which both availability and security requirements are the most important non-functional requirements.

What will be an ideal response?

Fundamentally, to provide availability, you need to have (a) replicated components
in the architecture so that in the event of one component failing, you can switch
immediately to a backup component. You also need to have several copies of the
data that is being processed. Security requires minimizing the number of copies of
the data and, wherever possible, adopting an architecture where each component
only knows as much as it needs to, to do its job. This reduces the chance of
intruders accessing the data.
Therefore, there is a fundamental architectural conflict between availability
(replication, several copies) and security (specialization, minimal copies). The
system architect has to find the best compromise between these fundamentally
opposing requirements.