An improved fastener comprising a fastener body orientated about a central axis and having a tool-engaging portion, a threaded fastening portion and a shroud-receiving portion having an inwardly facing annular groove orientated transverse to the central axis; a shroud concentrically mounted on the shroud-receiving portion to rotate relative to the fastener body under an applied external torque and having an axially-buckled radially-extending annular protrusion extending outwardly transverse to the central axis and disposed in the inwardly facing annular groove of the shroud-receiving portion of the body; the axially-buckled radially-extending annular protrusion of the shroud and the annular groove of the shroud-receiving portion of the body forming a shroud-retaining element restraining the shroud from movement in at least a first axial direction along the central axis.