PBC Library Manual 0.5.11 - Stanford Crypto Group

See Section 6.1 for how PBC gets random bits.
void element_random(element_t e)
If the e lies in a finite algebraic structure, assigns a uniformly random element to e.
4.9. Element import/export
Functions for serializing and deserializing elements.
int element_length_in_bytes(element_t e)
Returns the length in bytes the element e will take to represent
int element_to_bytes(unsigned char *data, element_t e)
Chapter 4. Element functions
Converts e to byte, writing the result in the buffer data. The number of bytes it will write can be determined
from calling element_length_in_bytes(). Returns number of bytes written.
int element_from_bytes(element_t e, unsigned char *data)
Reads e from the buffer data, and returns the number of bytes read.
int element_to_bytes_x_only(unsigned char *data, element_t e)
Assumes e is a point on an elliptic curve. Writes the x-coordinate of e to the buffer data
int element_from_bytes_x_only(element_t e, unsigned char *data)
Assumes e is a point on an elliptic curve. Sets e to a point with x-coordinate represented by the buffer data.
This is not unique. For each x-coordinate, there exist two different points, at least for the elliptic curves in PBC.
(They are inverses of each other.)
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