chat application using signal r and login

hi,

i want to create chat application in dotnet using signal r in which i want to send messages to group users and only registered user can login .
for which i need to match details with database .i searched alot on net but i dont find anything like login through database
everywhere using javascript signal r is implemented and chat is open for all. i want to make chat open to specfic user who
have valid login credentials and he then enters into chat room for that group.basically i want to send chat to only valid login users