Step 6: Round Head With Blank Head
I accidentally found this unique drive head system while working on the original Phillips project and since it did not apply there have since lost the specific information and the links. The remembered information is that it was a Japanese news article (google translated the webpage from Japanese) discussing a recent invention. The screw head has no markings and is round and blank. The screw head mimics a rivet, to discourage vandels. The driver utilized a heated ceramic head that when heated and the screw head expanded the grip would be tight enough to drive the screw. Once cooled the screw became virtually tamperproof unless heated by the same driver head unit.