The user of any one portable terminal sends a content information request
including a user ID to a distribution server. In response, the
distribution server distributes a stream data of content that can be used
on the user's terminal. If the user of a first portable terminal intends
to let a second portable terminal try out a certain content, the user
sends to the distribution server the trial permission information
including the user's own user ID, a content ID of the content of
interest, and a digital signature. The distribution server authenticates
the received information before distributing a streaming data of a
trial-oriented content with the content ID and user ID attached to it as
search keys. This allows the content that can be used on a given user
terminal to be tried out on another user terminal without the latter user
having recourse to the steps of searching for the content in question.