code: function _getMillerRabinIterations(bits) {
    if(bits <= 100) return 27;
    if(bits <= 150) return 18;
    if(bits <= 200) return 15;
    if(bits <= 250) return 12;
    if(bits <= 300) return 9;
    if(bits <= 350) return 8;
    if(bits <= 400) return 7;
    if(bits <= 500) return 6;
    if(bits <= 600) return 5;
    if(bits <= 800) return 4;
    if(bits <= 1250) return 3;
    return 2;
  }
docs: Returns the required number of Miller-Rabin iterations to generate a
  prime with an error probability of (1/2)^80.
  
  See Handbook of Applied Cryptography Chapter 4, Table 4.4.
  
  @param bits the bit size.
  
  @return the required number of iterations.