Extending profile fields. Hidden from public, visible for administrators and logged in users

Hey guys,

Is there a way / plugin to extend profile fields in wordpress that also enables to show / hide specific fields?

I want to add extra private profile fields (e.g. phone #, etc. ) for verification purposes, that show up after completing the registration process.
The registration process is straightforwarded: email / username and password. When editing profile, users have the ability to add extra information into the extended profile fields.

These private fields must be hidden from public but visible for the administrators and the logged in user; this way site administrators can do the verification process and avoid spamming, etc.

Any idea, suggestion?

Thank You!