Content transfer system, content transfer method, content transmitting apparatus, content transmission method, content receiving apparatus, content reception method, and computer program

A content transfer method for transferring content from a content transmitting apparatus to a content receiving apparatus through an external network in consideration of content protection, said method comprising:

• executing an authentication process between said content transmitting apparatus and said content receiving apparatus and sharing authentication information there between;
• and
• encrypting content to be transferred over the external network corresponding to a content request from said content transmitting apparatus and transferring the encrypted content from said content transmitting apparatus to said content receiving apparatus, wherein:
• a transfer process of the encrypted content over the external network is started in response to confirmation that the content request contains a keyword indicating that the content receiving apparatus has been authenticated,
• said keyword indicating that the content receiving apparatus has been authenticated is a keyword in a check level that said content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• said content receiving apparatus is informed of information regarding the keyword in the check level that the content transmitting apparatus supports.

A content transmitting apparatus for transferring content to a content receiving apparatus through an external network in consideration of content protection, said apparatus comprising:

• authentication process executing means for executing an authentication process with said content receiving apparatus and sharing authentication information;
• and
• content transfer process executing means for encrypting content to be transferred over the external network in accordance with a content request received from said content receiving apparatus and transferring the encrypted content to said content receiving apparatus, wherein:
• said content transfer process executing means starts a transfer process of the encrypted content over the external network in response to confirmation of validity of a keyword contained in the content request and indicating that the content receiving apparatus has been authenticated,
• said keyword indicating that the content receiving apparatus has been authenticated is a keyword in a check level that said content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• said content transfer process executing means informs said content receiving apparatus of information regarding the keyword in the check level that said content transmitting apparatus supports.

A content transmission method for transferring content to a content receiving apparatus through an external network in consideration of content protection, said method comprising:

• executing an authentication process and sharing authentication information with said content receiving apparatus;
• and
• encrypting content to be transferred over the external network in accordance with a content request received from said content receiving apparatus and transferring the encrypted content to said content receiving apparatus, wherein:
• a transfer process of the encrypted content over the external network is started in response to confirmation of validity of a keyword contained in the content request and indicating that the content receiving apparatus has been authenticated,
• said keyword indicating that said content receiving apparatus has been authenticated is a keyword in a check level that a content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• said content receiving apparatus is informed of information regarding the keyword in the check level that said content transmitting apparatus supports.

A content receiving apparatus for receiving content transmitted through an external network in consideration of content protection, said apparatus comprising:

• executing an authentication process and sharing authentication information with a content transmitting apparatus;
• and
• content transfer process executing means for issuing a content request that contains a keyword indicating that said content receiving apparatus has been authenticated and receiving encrypted content transferred over the external network in response to the content request, wherein:
• said keyword indicating that the content receiving apparatus has been authenticated is a keyword in a check level that said content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• said content transfer process executing means obtains information regarding the keyword in the check level that said content transmitting apparatus supports.

A content reception method for receiving content transmitted through an external network in consideration of content protection, said method comprising:

• executing an authentication process and sharing authentication information with a content transmitting apparatus;
• and
• issuing a content request containing a keyword indicating authentication completion and receiving encrypted content transferred over the external network in response to the content request, wherein:
• said keyword indicating authentication completion is a keyword in a check level that said content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• information regarding the keyword in the check level that the content transmitting apparatus supports is obtained.

A tangible computer readable medium storing a program for causing a computer system to execute a content transmission process for transferring content to a content receiving apparatus through an external network in consideration of content protection, said program comprising:

• executing an authentication process and sharing authentication information with the content receiving apparatus;
• and
• encrypting content to be transferred over the external network in accordance with a content request received from said content receiving apparatus and transferring the encrypted content to said content receiving apparatus, wherein:
• a transfer process of the encrypted content over the external network is started in response to confirmation of validity of a keyword contained in the content request and indicating that the content receiving apparatus has been authenticated,
• said keyword indicating that the content receiving apparatus has been authenticated is a keyword in a check level that a content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• said content receiving apparatus is informed of information regarding the keyword in the check level that said content transmitting device supports.

A tangible computer readable medium storing a program for causing a computer system to execute a content reception process for receiving content transmitted through an external network in consideration of content protection, said program comprising:

• executing an authentication process and sharing authentication information with a content transmitting apparatus;
• and
• issuing a content request containing a keyword indicating authentication completion and receiving encrypted content transferred over the external network in response to the content request, wherein:
• said keyword indicating authentication completion is a keyword in a check level that said content transmitting apparatus supports, and is one of a plurality of types of keywords that are different in check levels representing accuracy of authentication checks, and
• information regarding the keyword in the check level that said content transmitting apparatus supports is obtained.