Khalid Alhamed

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Currently many users trust binaries downloaded from repositories such as sourceforge.net. As with any system connected to the Internet, such repositories can be subject to attacks tampering with the distributed binaries (inserting viruses, changing behavior). We propose a mechanism to reduce the level of trust that users are required to have into(More)
We introduce protocols for a fully decentralized synchronization of data items among equal peers in an argumentation framework (for applications such as debates in petition signature drives, and deliberation among shareholders). Here, an argumentation is a structured exchange of justifications around issues (or motions). The motions are relevant to(More)
The discussed "Stacking the Deck" attack and our solution are relevant only to software controlled by loosely constituted communities. Developers can change their vision and abandon features that are essential for certain users. Moreover, well funded attackers can effectively take control of a project by orchestrating the transfer of the leadership of the(More)
DirectDemocracyP2P 5 is an open source platform developed in JAVA and offering peer-to-peer and mobile ad hoc wireless communication capabilities. The platform offers an API supporting plugins, beside its main application: deliber-ative petition drives (aka citizens' initiatives with integrated argumentation) [1]. An authentication-by-reputation technique(More)
In this study, we introduce a new peer-to-peer (P2P) approach to instant messaging systems based on a fully decentralized network, and where each human owning a peer can control the traffic supported by her system. The control may be based on criteria such as: (a) her desire to help the endpoints of the communication, e.g., based on friendship, (b) her(More)
We focus on the problem of selecting reviewers (or raters) that are considered by a recommender system (or a user) under the aspect of security. Malicious reviewers can exert unreasonable influence, and can bias online consumers unfairly against an attacked item or competitor. This paper proposes an approach where a meta-recommender maximizes the aggregated(More)
A JAR (Java Archive) is typically used to incorporate code and associated resources into one file to distribute Java software. A cryptographically signed JAR file provides assurance about the authorship of the contents of the archive. We use Signed JAR files as part of a recommendation system. In this system different recommenders will evaluate the same(More)
Peer-to-peer infrastructures in a world where many systems are mobile, or found behind NATs and firewalls that cannot be programmed by users, require significant support from computers with appropriate connectivity, called supernodes. We introduce a new fully decentralized unstructured peer-to-peer (P2P) approach to open-source instant messaging systems(More)