I was sure it was a 8mm allen socket. I sold mine, so can't confirm, but I replaced mine with the HMV heavy bar ends and they are 8mm. Disregard that star looking thing in the middle, it's an allen around it.
Entirely possible they fit onto the tooling better for mass production assembly.
I know my students can destroy a phillips bit when using a power screwdriver for assembly of parts in woods class. They do a bit better with square drive and far better with torx drive, but still a lot of them destroy the bits because they can't hold the drill straight to the fastener. I'm betting those tamper resistant fasteners hold even better on the bit tip.
Pick up a set of the bits. Oh, and consider putting your country of residence in your user CP (control panel) to give people a general hint of where you are located for better references like where to find something like a tool or a shop. If you aren't in the U.S. the links I provided are probably useless, but odds are you can find what you need near you.