Making saucisson sec from salami at home
While you might be technically correct if you were to call saucisson sec a salami, you do not make saucisson sec from commercial salami. Without knowing how the salami was produced it could be dangerous to try to do so.  The pictures you posted seems to be of a cooked salami, which is significantly more perishable than its uncooked cousins.

Traditionally, both saucisson sec and salami are dry cured sausages, but they can have significant differences in terms of ingredients and process. Saucisson is usually a coarse ground, pork based sausage lightly seasoned with garlic.  Salami is usually more finely ground, pork or pork-beef sausage often seasoned with coriander, ginger, and nutmeg. Salami is usually fermented with an added lactobacillus bacteria culture, saucisson sec can be made with or without an added culture. Both can be found with or without a covering of penicillium mold.

See also:

Is there a difference between &#39;Saucisson Sec&#39; and &#39;Salami&#39;?

http://www.popsugar.com/food/Difference-Between-Charcuterie-Salumi-Salami-3368740