code: private BigInteger nextK() {
  		final int qBitLength = this.ecParams.getN().bitLength();
  
  		BigInteger k;
  		do {
  			k = new BigInteger(qBitLength, this.random);
  		} while (k.equals(ECConstants.ZERO) || k.compareTo(this.ecParams.getN()) >= 0);
  
  		return k;
  	}
docs: 下一个K值
  
  @return K值