UnsecuredLayoutsPageBase class
Represents the base class for application pages that explicitly do not require the user to have any permissions, such as the access denied page.
System.Web.UI.Control
System.Web.UI.TemplateControl
System.Web.UI.Page
Microsoft.SharePoint.WebControls.DeltaPage
Microsoft.SharePoint.WebControls.UnsecuredLayoutsPageBase
Microsoft.SharePoint.WebControls.LayoutsPageBase
Namespace: Microsoft.SharePoint.WebControls
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
In general, use UnsecuredLayoutsPageBase as a base class for pages to which even unauthenticated users must have access, such as a login page.
For a page base control to which access can be limited to users who possess certain rights, use LayoutsPageBase.
Typically, a class is created in a code behind the file (.aspx.cs) that derives from UnsecuredLayoutsPageBase. The .aspx file, in turn, inherits from the custom page class. For example, the %ProgramFiles%\Common Files\Microsoft Shared\web server extensions\15\TEMPLATE\LAYOUTS\login.aspx page that ships with Microsoft SharePoint Foundation 2010 inherits from an internal class named LoginPage, which itself inherits from UnsecuredLayoutsPageBase.