Method of collecting peer-to-peer-based content sending/reception information

A method of collecting peer-to-peer (P2P)-based content sending/reception information, the method comprising:

• storing, by a server, a value of a public key of a first peer and a value of a public key of a second peer;
• exchanging, by the first peer and the second peer, a buffer map of the first peer with a buffer map of the second peer;
• requesting, by the first peer, the second peer to send a piece of content;
• sending, by the second peer, the piece of content to the first peer;
• when reception of the piece of the content is completed by the first peer, generating, by the first peer, a receipt message providing notification that the piece of content has been correctly received and then signing, by the first peer, the receipt message with a private key of the first peer;
• sending, by the first peer, the signed receipt message to the second peer;
• verifying, by the second peer, integrity of the signed receipt message using the public key of the first peer;
• when the second peer determines that there is no error in the integrity of the signed receipt message, signing, by the second peer, the signed receipt message again;
• sending, by the second peer, the dually signed receipt message to the server;
• and
• checking, by the server, integrity of the dually signed receipt message using the public key of the first peer and the public key of the second peer.