Type A

Pairings on type A curves are the fast and ought to be used where the main concern is efficiency. Typically, r should be about 160 bits long and q about 512 bits. In this case, elements of groups G1 and G2 take 512 bits to represent.

The file param/a.param contains parameters for a type A pairing suitable for cryptographic use.

The a_param_t data type holds parameters for a type A pairing.

void a_param_init(a_param_t p): Initialize p. This must be called before p can be used.
void a_param_clear(a_param_t p): Clear p. This should be called after p is no longer needed.
void a_param_gen(a_param_t p, int rbits, int qbits): Generate type A pairing parameters and store them in p, where the group order r is rbits long, and the order of the base field q is qbits long. To be secure, generic discrete log algorithms must be infeasible in groups of order r, and finite field discrete log algorithms must be infeasible in finite fields of order q^2. Typical values: rbits = 160, qbits = 512.
void a_param_out_str(FILE *stream, a_param_t p): Write the parameters in p in a text format onto stream.