A tamper-proof fastening mechanism, a fastener and a safety apparatus that allow fastening at least two elements to one another, where the fastener includes a pin portion that has a mechanism for enhancing the pin grip to a socket walls for enhancing the fastening thereto, where the socket is perforated between the elements. According to one embodiment, the mechanism includes an expansion mechanism in which a portion of the pin can expand once inside the socket. According to other embodiments, the mechanism includes a plurality of fasteners each including a pin that is rotatable to a different rotation direction for fastening and removal thereof, where they all appear the same when fastened making it more difficult for an unauthorized person to know in which direction to rotate each for removal thereof.