Information processing apparatus

An information processing method for use with an information processing apparatus for providing a device node key used to decrypt an enabling key block included in a content, said information processing method comprising the steps of:

• assigning uniquely a second information processing apparatus to a leaf subordinate to said first node in a key-managed hierarchical tree structure having a content provision category assigned to a first node on a given level of the structure;
• and
• providing said second information processing apparatus with said device node key corresponding to a path between said leaf assigned in said assigning step and said first node.

A storage medium which stores a computer-readable program for use with an information processing apparatus for providing a device node key used to decrypt an enabling key block included in a content, the program comprising the steps of:

• assigning uniquely a second information processing apparatus to a leaf subordinate to said first node in a key-managed hierarchical tree structure having a content provision category assigned to a first node on a given level of the structure;
• and
• providing said second information processing apparatus with said device node key corresponding to a path between said leaf assigned in said assigning step and said first node.

A program executable by a computer for controlling an information processing apparatus for providing a device node key used to decrypt an enabling key block included in a content, said program causing said computer to carry out the steps of:

• assigning uniquely a second information processing apparatus to a leaf subordinate to said first node in a key-managed hierarchical tree structure having a content provision category assigned to a first node on a given level of the structure;
• and
• providing said second information processing apparatus with said device node key corresponding to a path between said leaf assigned in said assigning step and said first node.

An information processing apparatus for providing a license granting the use of a content, said information processing apparatus comprising:

• receiving means for receiving from a second information processing apparatus leaf identification information for identifying in a key-managed hierarchical tree structure a leaf assigned to said second information processing apparatus;
• and
• transmitting means which, if said leaf identification information received by said receiving means identifies a leaf subordinate to a first node on a given level of the structure, said first node being assigned a content provision category, then transmits said license including said leaf identification information to said second information processing apparatus.

An information processing method for use with an information processing apparatus for providing a license granting the use of a content, said information processing method comprising the steps of:

• receiving from a second information processing apparatus leaf identification information for identifying in a key-managed hierarchical tree structure a leaf assigned to said second information processing apparatus;
• and
• transmitting said license including said leaf identification information to said second information processing apparatus if said leaf identification information received in said receiving step identifies a leaf subordinate to a first node on a given level of the structure, said first node being assigned a content provision category.

A storage medium which stores a computer-readable program for use with an information processing apparatus for providing a license granting the use of a content, the program comprising the steps of:

• receiving from a second information processing apparatus leaf identification information for identifying in a key-managed hierarchical tree structure a leaf assigned to said second information processing apparatus;
• and
• transmitting said license including said leaf identification information to said second information processing apparatus if said leaf identification information received in said receiving step identifies a leaf subordinate to a first node on a given level of the structure, said first node being assigned a content provision category.

A program executable by a computer for controlling an information processing apparatus for providing a license granting the use of a content, said program causing said computer to carry out the steps of:

• receiving from a second information processing apparatus leaf identification information for identifying in a key-managed hierarchical tree structure a leaf assigned to said second information processing apparatus;
• and
• transmitting said license including said leaf identification information to said second information processing apparatus if said leaf identification information received in said receiving step identifies a leaf subordinate to a first node on a given level of the structure, said first node being assigned a content provision category.

An information processing apparatus for offering contents, comprising:

• receiving means for receiving a content request including content identification information for identifying a content;
• and
• transmitting means for transmitting an encrypted content including an enabling key block decryptable by use of a device node key corresponding to a path between a leaf subordinate to a first node on a given level of a key-managed hierarchical tree structure, and said first node which is assigned a content provision category.

An information processing method for providing contents, comprising the steps of:

• receiving a content request including content identification information for identifying a content;
• and
• transmitting an encrypted content including an enabling key block decryptable by use of a device node key corresponding to a path between a leaf subordinate to a first node on a given level of a key-managed hierarchical tree structure, and said first node which is assigned a content provision category.

A storage medium which stores a computer-readable program for use with an information processing apparatus for providing contents, the program comprising the steps of:

• receiving a content request including content identification information for identifying a content;
• and
• transmitting an encrypted content including an enabling key block decryptable by use of a device node key corresponding to a path between a leaf subordinate to a first node on a given level of a key-managed hierarchical tree structure, and said first node which is assigned a content provision category.

A program executable by a computer for controlling an information processing apparatus for providing contents, said program causing said computer to carry out the steps of:

• receiving a content request including content identification information for identifying a content;
• and
• transmitting an encrypted content including an enabling key block decryptable by use of a device node key corresponding to a path between a leaf subordinate to a first node on a given level of a key-managed hierarchical tree structure, and said first node which is assigned a content provision category.