You can declare a static property CookieAuthOptions if you configured CookieAuthOptions in ConfigureAuth or any other AuthOption should also implement ISecureDataFormat<AuthenticationTicket>(eg: OAuthBearerOptions.AccessTokenFormat). This one contains Protect & Unprotect methods.
Whenever you need to access AuthenticationProperties, you have to be able to get a grip of Owin context to get a reference to a ticket that implements your correct format.
As a basic example steps,
Startup.cs => public static CookieAuthenticationOptions CookieAuthOptions;
Startup.cs => ConfigureAuth => CookieAuthOptions.CookieName = "xxx";
BaseController.cs => Startup.CookieAuthOptions.TicketDataFormat.Unprotect(Request.Cookies["xxx"].Value).Properties;
to get what you want.
PS: You did not mention where you need this and I assumed it would be in a controller.