MVC4 C# - Authentication over a Link (like Dropbox file sharing with access over a link)?

MVC4 C# - Authentication over a Link (like Dropbox file sharing with
access over a link)?

i want to create a MVC4 Web Application with C# with the function that i
can sharing videos and other files over a Hyperlink Access Control like in
Dropbox or Skydrive.
How can i solve this idea to a great application.
Functions: + Access to a Video, Files and Images over a Link (Hyperlink) +
The Accesslink should be generateted for each user + The should be
automactially expire fr example in about 24h ....
Please can anyone give me a great idea or tips t can solve this idea.
Thank you