High-growth companies can be difficult to find in the information technology security business, but Vasco Data Security International ( VDSI), which makes online authentication products, could prove to be an exception. With growth rates well above the industry standard, an ascending stock and a federal directive for banks to strengthen their online banking security, Vasco is poised for an interesting year. The company, which has a market cap of $495 million, has already started the year with a bang: Vasco's stock has risen about 17% in the first four days of trading and is up by nearly two-thirds in the past six months. Shares of Vasco were recently up 68 cents, or 5%, to $14.35. Vasco's momentum is partly based on a set of guidelines issued by the Federal Financial Institutions Examinations Council in 2005, asking U.S. banks to strengthen their online banking security by using "two-factor authentication" -- a process in which a user would have to be offered an added layer of security in the form of a smart card or token in addition to his password. The FFIEC is a group that includes the Federal Reserve, the Federal Deposit Insurance Corp., the National Credit Union Administration and the Office of the Comptroller of the Currency. Banks are expected to adopt some form of two-factor authentication by the end of 2007, the FFIEC said.