How are vCenter credentials stored in NB?

Hello,

I was trying to find an answer to question "How are the vCenter credentials stored in NB?" in online documentation and on this forum, but I was not successful.

Does anybody know how are the credentials stored? Is there any internal database/file on Master server? And is it also encrypted - so let's say safe against any security threat?

Using NB 10.1.1 on Windows.

Thank you.
Tomas