5.2.2 Encoding

5.2.2 Encoding

All values are coded as octet strings, and integers are coded using little-endian convention, i.e., a 57-octet string h h[0],...h[56] represents the integer h[0] + 2^8 * h[1] + ... + 2^448 * h[56].

A curve point (x,y), with coordinates in the range 0 <= x,y < p, is coded as follows. First, encode the y-coordinate as a little-endian string of 57 octets. The final octet is always zero. To form the encoding of the point, copy the least significant bit of the x-coordinate to the most significant bit of the final octet.