A content distribution system for performing multicasting of one and the same content from a mobile communication network system to a plurality of mobile communication terminals, said network system having: means for allocating a multicasting channel between said network system and said mobile communication terminals to perform multicasting of content and distributing a multicasted content to said mobile communication terminals, means for receiving a request to resend said content from a mobile communication terminal which fails in receiving said multicasted content, means for allocating an individual channel between said network system and said mobile communication terminal which requests re-distribution of content, and re-distributing means for re-distributing said content from said network system to said mobile communication terminal which requests re-distribution of said multicasted content by using said individual channel, characterized in that said network system further comprises verification means for verifying whether or not said mobile communication terminal which requests to resend said content is a proper mobile communication terminal, wherein said verification means is adapted to a) store a random number and a calculation result of an authentication calculation based on said random number at a xGSN, b) to send said random number to a mobile communication terminal, c) to receive said calculation result of said authentication calculation based on said random number calculated by said mobile communication terminal, and d) to judge that said mobile communication terminal is the proper authenticated mobile communication terminal, in a case in which said stored calculation result and said received calculation result coincide, and said re-distributing means is adapted to perform re-distributing of said content by using said individual channel to said mobile communication terminal which requests re-distribution of said multicasted content, in a case in which said network system verified that said mobile communication terminal which requests to resend said content is a proper authenticated mobile terminal, wherein said xGSN is a serving general packet radio service support node or a gateway general packet radio service support node. means for allocating a multicasting channel between said network system and said mobile communication terminals to perform multicasting of content and distributing a multicasted content to said mobile communication terminals, means for receiving a request to resend said content from a mobile communication terminal which fails in receiving said multicasted content, means for allocating an individual channel between said network system and said mobile communication terminal which requests re-distribution of content, and re-distributing means for re-distributing said content from said network system to said mobile communication terminal which requests re-distribution of said multicasted content by using said individual channel, characterized in that said network system further comprises verification means for verifying whether or not said mobile communication terminal which requests to resend said content is a proper mobile communication terminal, wherein said verification means is adapted to a) store a random number and a calculation result of an authentication calculation based on said random number at a xGSN, b) to send said random number to a mobile communication terminal, c) to receive said calculation result of said authentication calculation based on said random number calculated by said mobile communication terminal, and d) to judge that said mobile communication terminal is the proper authenticated mobile communication terminal, in a case in which said stored calculation result and said received calculation result coincide, and said re-distributing means is adapted to perform re-distributing of said content by using said individual channel to said mobile communication terminal which requests re-distribution of said multicasted content, in a case in which said network system verified that said mobile communication terminal which requests to resend said content is a proper authenticated mobile terminal, wherein said xGSN is a serving general packet radio service support node or a gateway general packet radio service support node.