function EdwardsCurve(conf) {
  // NOTE: Important as we are creating point in Base.call()
  this.twisted = (conf.a | 0) !== 1;
  this.mOneA = this.twisted && (conf.a | 0) === -1;
  this.extended = this.mOneA;

  Base.call(this, 'edwards', conf);

  this.a = new BN(conf.a, 16).umod(this.red.m);
  this.a = this.a.toRed(this.red);
  this.c = new BN(conf.c, 16).toRed(this.red);
  this.c2 = this.c.redSqr();
  this.d = new BN(conf.d, 16).toRed(this.red);
  this.dd = this.d.redAdd(this.d);

  assert(!this.twisted || this.c.fromRed().cmpn(1) === 0);
  this.oneC = (conf.c | 0) === 1;
}
Returns the ethereum public key of a given private key
@param {Buffer} privateKey A private key must be 256 bits wide
@return {Buffer}