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Boosted by glyph ("Glyph"):
whbboyd@infosec.exchange ("Will") wrote:
@glyph Okay, I can't resist.
So the overhead for the HID protocol is 8x for a single keypress. (I don't think the HID protocol can actually saturate a 10Gb/s link, but we're going to ignore that for now.) That means for a stream of single keystrokes, you're sending just under 170 million per second. (You can send more data by chording, up to six bytes per poll, but you won't get anything out of pressing individual keys faster than that.) We'll optimistically assume that your keyboard has 102 keys (as we know it doesn't) and that you're pressing each of those 102 keys equally often (as we know you're not). That means each key is getting pressed about 1.6 million times per second.
By the standardized definition of WPM for typing, this is 329 thousand words per minute.
I dunno exactly what the throw of your keyswitches is, but if it's a standard-ish 4mm, then in order to be pressed in 300 nanoseconds, it will need an average speed of 47 thousand km/hr. Under constant acceleration from your fingertip, it will accelerate at 86.5 billion m/s², bottoming out at 94.6 thousand km/hr and delivering some 350 kJ to the backplate. (This is about the energy in 75 grams of TNT.) The force required for this keypress is 86 meganewtons, or 8.8 metric tonnes. This *may* result in breaking a fingernail, or possibly some finger strain. (Also, the return spring will have to be as strong, meaning the press force will be even greater.)
