Summary by Sasha - the fundamental idea behind this paper is in providing a P2P application - that will support anonymity of both authors and readers - protocol does not guarantee data availability or life-time; if data is not - popular it will fade out and eventually all cached copies of data will - disappear - protocol learns usage patterns through node requests and responses and - builds most optimal routes - routes are based on semantic-closeness of data which is built not on - data/file descriptions (which are textual) but on hashes, which evenly - distribute any related files over the network - author discusses different tasks in the network; retrieving data, storing - data - naming together with searching and updating is a serious part of research - involving additional approaches, like additional indirect (file) access, - signature -verified indirect files, contenthash keys, etc - they discuss splitting files in smaller chunks with references stored in - indirect files - further, author discusses security issues, possible attacks both from - internal and external attacks, presenting importance of non-probabilistic - routing that protects against statistical analysis attacks Summary by Adnan Single point of failure is an important aspect under data management. For instance if we take it from security point of view then, if a centralized system is compromised then it can cause problems at a bigger scale. A huge number of audiences will be affected. There are various solutions out there dealing with data management based on either centralized or decentralized system. This paper introduces such a system which is based on the concept of decentralized system. Free net is a system which allows to store data over a network on different nodes. The paper does a detailed research on how the data will be stored, fetched on/from the nodes. The data is stored among different nodes, so the nodes availability is important aspect. Freenet is software available to download. Freenet is based on five main design goals including Anonymity for both producers and consumers of information, Deniability for storers of information, Resistance to attempts by third parties to deny access to information, Efficient dynamic storage and routing of information and Decentralization of all network functions. Freenet is implemented as a peer to peer network of nodes that query one another to store and retrieve data les which are named by location independent keys. A packet in a freenet protocol contains self-oriented messages. It supports both TCP and UDP but it prefers TCP, when available. Naming, searching and updating data has been discussed in the paper and concept of content hash key is used for that. Performance has been measured by carrying out simulation. Different security aspects are also considered specially routing. The Freenet network provides an effective means of anonymous information storage and retrieval. The work on freenet is still in progress bit around 15,000 copies has been download and it¨ªs in use. Summary by Patrick In this paper the authors propose a peer-to-peer distributed storage system that allows anonymous storing, replication and retrival of files while protecting the identity of both publishers and readers. Files are stored using either one of two kinds of keys. Content-Hash key and signature-verifying key. The content-hash key is a hash based on the content of the file (SHA-256) and the signature-verifying key is based on public/private keys. Evaluation is done by simulating a system and comparing the successful requests against a different number of nodes. I found that the evaluation part was lacking in details and they could probably have done a more thorough job. The authors also talk about different security aspects, how to protect anonymity, prevention of insert-spamming, modification of files and other potential attacks. However, I don't think they cover a lot of potential attack vectors. They suggest using a hash cash scheme to protect against users from spamming large garbage files in order to overwrite genuine files, but it would be possible to attack such a system with a botnet. An attack vector not covered by the paper, but that I think is quite important is that encryption is optional. They suggest that files should be encrypted to protect the storage-users from knowing what they are storing. A malicious user (or a group of users) could spam the network with unencrypted illegal files to threaten both the networks authenticity as well as creating fear for individual storage users. Summary by Zahid Freenet: A Distributed Anonymous Information Storage and Retrieval System Summary: The computer networks are growing very rapidly in a large scale so the importance of storage and exchange of information is also going high. Regarding to user¡¯s privacy the information is typically store only one or a few fixed places so the privacy is on high risk. There are many reasons but on of them is to creating a central point to store or exchange the information. It would be very easy for opponents to remove or hack the data from a central system or location. System need greater security and reliability, just because of this reasons the authors suggest new system called Freenet, a distributed information storage and retrieval system design to address these concerns of privacy and availability. Freenet works under the concept of peer-to-peer network of nodes that query one another to store and retrieve data files, which are named by location independent keys. Freenet has one good future that, it enables users to share unused disk space. Freenet operates as a location independent distributed file system across many individual computers that allows files to be inserted, stored and requested anonymously. Freenet has five main goals like as follow 1) Decentralization of all network functions. 2) Efficient dynamic storage and routing of information. 3) Anonymity for both producers and consumers of information 4) Resistance to attempts by third parties to deny access to information 5) Deniability for storers of information According to authors that it is not intended to guarantee permanent file storage, although it is hoped that enough nodes will join with enough storage capacity that most tiles will be able to remain indefinitely. Freenet is a free software project on Sourceforge. Summary by Ioana Freenet: a distributed anonymous information storage and retrieval system. Ian Clarke, Oskar Sandberg, Brandon Wiley, and Theodore W. Hong. In this paper, the authors propose Freenet, a peer-to-peer application that is designed to offer anonymity of sender and receiver of the data. The system is constructed of a network of identical nodes, which provide storage for data files and cooperate to obtain efficiency routing of messages. The proposed solution is based on queries send by the nodes in the network to retrieve or insert data files. The messages are passed from a node to another, and a node knows only the previous and the next hop. There are two types of transactions that can occur : retrieve and insert data in the networks. For each of these two, different messages are used : - Retrieve data : ¡°Request.data¡± send by the node that is requesting the data; ¡°Reply.Restart¡± send by remote nodes, while the request is processed; ¡°Send.Data¡±, if the request is successful ¡°Reply.NotFound¡± in case the data which was requested is not found. - Insert data : ¡°Request.Insert¡± ¡°Reply.Restart¡± ( same as for retrieving data) ¡°Send.Data¡± and ¡°Reply.NotFound¡± ¡°Request.Continue" "Reply.Insert" and ¡°Send.Insert¡±; Apart from the messages exchanged during the two transaction, in the beginning of such an action a ¡°Request.Handshake¡± and ¡°Reply.Handshake¡± are exchanged. In order to evaluate the performance of the system, the authors use simulations in which different number of nodes are used( from 500 to 900 nodes), each having a storage size of 40 items and a routing table of 50 addresses. The authors evaluate the retrieval time and the retrieval success rate. The main findings are : - for the retrieval time, ( measured in number of hops needed for a successful request): for all the size of the networks, the value stabilises around 10 request. - for the retrieval success rate : the number of queries necessary until the network converges is approximately half of the network size( for 500 nodes this value is equal to 300, whereas for 900 nodes is less than 600). In order to evaluate the security, the authors employ a taxonomy of anonymous communication properties on three axes : sender anonymity/receiver anonymity , local eavesdropper and the degree of anonymity.