Help with ECDSA (crypto)

maxhavoc

Hi, I know next to nothing about the mathematical aspects of ECDSA, this kind of stuff is way beyond me, yet at my job, I'm tasked with a certain problem. I am given a set of inputs to an ECDSA signature verification function. I know that one of the paramters that I need is a point on the curve, but I am given the point as a seperate X and Y value, how do I combine that to make a single point? I'm using K-163 as the key size. So the length of the point should be 21 bytes. I am given two 22 byte values (extra byte due to a leading '0' and so not important). Can I just XOR the two values?