Switzerland has handed U.S. authorities encrypted data on bank employees who served American clients suspected of dodging taxes, and will only provide the key to decipher them once a tax row is settled, Reuters quoted finance ministry as saying on Tuesday. Swiss banks have provided tens of thousands of pages of encrypted data on their U.S. businesses, including names of client advisers, a finance ministry spokesman said. The data transfer came after Swiss media reported the U.S. authorities had set a Jan. 30 deadline for banks under investigation -- including Credit Suisse, Julius Baer and Basler Kantonalbank -- to deliver data on their U.S. offshore business or face possible prosecution. "We will only decode when we have found a solution with the United States on all the banks that are under discussion," finance minister Eveline Widmer-Schlumpf told Swiss television.