Sensitive data transmission

I'm new to the whole wireless world, so thank you for bearing with me.

My question is if I was attempting to pass sensitive data from a remote source back to a source, what encompasses the whole process of passing the data including cryptography, hardware, the whole kaboodle??

I am doing research for a project and it deals with passing data from a visiting doctor back to its home base. So, very sensitive data. Would I use Wifi?? I appreciate anyone who can point me in the right direction.