Do not know if this project still accept new enhancement, this change can improve pairing performance more than 30%. https://github.com/emmansun/bn256/commit/b532ebb0ff76a27de8ec9c5a05956c5823bb36ba Reference: - [Fast Squaring in the Cyclotomic Subgroup](https://www.iacr.org/archive/pkc2010/60560212/60560212.pdf) - [dclxvi](https://github.com/agl/dclxvi/blob/master/fp12e.c#L274)