connect USB keyboard to Arduino using clk and data wires
USB doesn't have data and clock lines. It has a pair of data lines with inverted polarity (D+ and D-). The USB protocol is considerably more complex than you seem to imagine.
However there is a caveat: some keyboards have the ability to work in IBM PS/2 mode. For this you will need a USB to PS/2 adaptor (pictured below) and then use the PS2Keyboard.h library. Your mileage may vary, though, as not all keyboards will work.