CRM dynamics in a low trust help scenario

Well, imagine that the bank has a call center in which employees with a low level of trust work. Employees must provide basic services to customers over the phone. Call center employees receive calls from the client, ask them specific security questions, and then service the accounts in some way.

Now, from the client’s point of view, the bank checks who they are by asking security questions. This is subtly different from the banking point of view: it checks that the call center employee is talking to the client.

Why is this difference important? The bank wants to limit these employees with low confidence, so they cannot view any account information until the customer calls them. Therefore, a call center employee cannot view customer account information that did not just contact him and ask for services.

So the question is: Is such a setting possible in Dynamics CRM 2011? How can you implement it? Some level of customization will be fine, but a custom CRM data driven application is not.

I think it’s possible to create a custom component that temporarily changes the user’s write permissions (and all its children) after answering some security questions. However, I'm not even sure if write-based security (outside of Ownership) is supported in CRM ...? I assume that you can temporarily assign ownership to the user. Is it wise?

Please Note: Simply hiding views and finding buttons from the GUI is not the level of security we are looking for here. We strive to literally limit the user access to the data in question.