Distributing data to multiple clients from server

A program for distributing data to a plurality of clients from a server, the program causing a computer to execute the steps of:

• generating a common noise by using noises unique to the plurality of clients, respectively;
• embedding the common noise in the data to be distributed to make the data unusable;
• and
• distributing the data containing the embedded common noise, so that the data containing the embedded common noise is made usable by each of the plurality of clients using a unique noise generated in the client.

A system for distributing data to a plurality of clients from a server, the system comprising:

• a unit configured to generate a common noise by using noises unique to the plurality of clients, respectively;
• a unit configured to embed the common noise in the data to be distributed to make the data unusable;
• and
• a unit configured to distribute the data containing the embedded common noise, so that the data containing the embedded common noise is made usable by each of the plurality of clients using a unique noise generated in the client.