The 25-year-old former Basel player, who will compete with Alvaro Arbeloa and Steve Finnan for the right-back berth, has signed a four-year deal.
"His strength is going forward," Benitez told Liverpool's website when the agreement was confirmed. "He is an offensive player with great energy and a winning mentality.
"He also played in the Champions League during his time with Basel and so is used to top-level football.
"He is a good signing, a player of potential, who can help us improve in the wide areas."