Implementing DELETE function in a trusted P2P network Hiroshi Isozaki and Syed Wasif Haider [Aim] Currently popular peer-to peer networks like BitTorrent do not include a function to delete specific data. The absence of this feature is in line with the one of the initial aims of P2P networks ,i.e to counter censorship. However, as a result, deletion of content stored over a P2P network is a non-trivial task. Firstly large organizations managing content over a peer-to-peer network (distributed) may need to invalidate data that, over time, has been cached by the peer nodes. Secondly each node should behave in the manner specified in the specification to avoid an illegitimate node rejects the command to delete the target content. We propose a model in which an organization manages content in a trusted peer-to-peer network for content distribution. Any node can upload data into the P2P network. The administrator is given the authority to carry out delete function to remove data that has ,for instance, expired or data that the organization simply does not want to remain on the network. We also aim at evaluating the effectiveness of our proposed mechanism. [Issues to be addressed] This approach involves two basic questions. The first is how to implement delete functionality in the P2P network. Many approaches are possible here, having different impact on considerations of efficiency and overhead. There also exists the problem of a non-active node while performing delete. Another issue in our model is the question of guaranteeing access to the P2P application to only trusted nodes. If an untrusted node exists in the network, it may simply ignore the delete command leading to an inconsistent state or ineffective delete. Therefore a node should attest the code of other nodes before accepting a request. To achieve code attestation, we assume the existence of TPM (Tamper Proof Module). [Expected results] We expect that our proposed deletion mechanism shall work as specified above, in a trusted P2P network.