Verification of content possession by an announcing peer in a peer-to-peer content distribution system

In a peer-to-peer content distribution system including a plurality of peer nodes operably linked to a tracker node, a method, carried out by a processor associated with the tracker node, comprising:

• receiving, from an announcing node of the peer nodes, a message including indicia of a content item claimed to be possessed by the announcing node;
• identifying a content storage node possessing the content item;
• requesting a challenge from the content storage node;
• receiving the challenge from the content storage node, wherein the challenge is based on a random portion of the content item;
• receiving an expected challenge response from the content storage node;
• issuing the challenge to the announcing node;
• receiving a challenge response from the announcing node;
• and
• verifying the announcing node's possession of the content item if the challenge response matches the expected challenge response.

Apparatus for verifying content possession by a peer node, in accordance with a peer-to-peer content distribution system including a plurality of peer nodes operably linked to a tracker node, the apparatus at the tracker node comprising:

• a peer node interface;
• a content storage node interface;
• a memory;
• and
• at least one processor operably coupled to the peer node interface, content storage node interface and memory and configured to:
• (a) receive, from an announcing node of the peer nodes, a message including indicia of a content item claimed to be possessed by the announcing node;
• (b) obtain the content item;
• (c) select a random portion of the content item;
• (d) formulate a challenge based on the random portion of the content item;
• (e) determine an expected challenge response;
• (f) issue the challenge to the announcing node;
• (g) receive a challenge response from the announcing node;
• and
• (h) verify the announcing node's possession of the content item if the challenge response matches the expected challenge response.

Apparatus for verifying content possession by a peer node, in accordance with a peer-to-peer content distribution system including a plurality of peer nodes operably linked to a tracker node, the apparatus at the tracker node comprising:

• a peer node interface;
• a content storage node interface;
• a memory;
• and
• at least one processor operably coupled to the peer node interface, content storage node interface and memory and configured to:
• (a) receive, from an announcing node of the peer nodes, a message including indicia of a content item claimed to be possessed by the announcing node;
• (b) identify a content storage node possessing the content item;
• (c) request a challenge from the content storage node;
• (d) receive the challenge from the content storage node, wherein the challenge is based on a random portion of the content item;
• (e) receive an expected challenge response from the content storage node;
• (f) issue the challenge to the announcing node;
• (g) receive a challenge response from the announcing node;
• and
• (h) verify the announcing node's possession of the content item if the challenge response matches the expected challenge response.