1. A Novel approach to Bind-over Sybil nodes in a swarm Zhang Bhanu Kaushik Deep Kamal Singh Xiang Cui

2.  HostClient sends a request to Tracker.  Tracker- Provides.torrent file containing information of the other clients.  Clients - Performs both Upload and Download.  HostClient communicates with the clients received in.torrent.  Clients exchange pieces (different strategies) & match their hashes with those received in.torrent.

3.  The Ostra  Samsara: “Honor among thieves”  Cheating strategies in BitTorrent ◦ BitThief ◦ BitTyrant ◦ Under-reporting strategy ◦ Collusion in BitTorrent

4.  Using the trust relationships to eliminate a trusted certificate authority.  Restrict unwanted communication from “Sybil- nodes”.  User with multiple identities can send additional unwanted communication by making additional relationships.  Every client in the swarm gets a “Fair-share”

5. 1. A trusted entity (Tracker) observes all actions for every client and associates them with the identity of the Client performing the action 2. Every Client classifies the received packets of data as wanted or unwanted. 3. There is a non-trivial cost for initiating and maintaining links in the network.

6.  All the transactions consists of three phases.  Authorization -Tracker checks if the transaction can be approved and a token could be issued to the sender.  Transmission – As per the token, sender takes the necessary action.  Classification – Receiving client classifies the communication (Good or Bad) & provides feedback to Tracker

7.  Use link credit instead of user credit.  Directional credit design  Each link with a link credit balance B, initial value 0, and range [L, U]. With L <= 0 <= U, and L<= B <= U.

8.  A client before a transaction requests the Tracker for approval.  On the reply, the transaction is declined or approved.  Initial credit of 20 Mb is assigned to every link  Receives a request for transaction from sender.  Issues a token for the transaction.  After the receiver’s classification, makes the necessary credit adjustments. At ClientAt Tracker

9.  Simulated on 80 Planet-Lab hosts all around the world (MA, NY, CA, India, Canada, Hong Kong China, Taiwan etc.).  Tracker – CCIS Lab Machine (God save TimePilot !!).  Simulation subjects a. 924 MB b. 693 MB c. 81 MB

10.  Performance of original snark  Credit-based Tracker, without sybil nodes in swarm.  Comparison with sybil nodes in snark  Credit-based Tracker, with sybil nodes in swarm.

11.  Implementing the system using a decentralized mechanism.  Using the social network to gather the torrent information.  Developing and implementing a new Incentive mechanism for untrustworthy clients.

12.  Data is collected and plotted for all nodes including Tracker  Attributes :- ◦ Downloaded ◦ Uploaded ◦ Remaining ◦ Event ◦ TimeStamp