An Optimistic Mandatory Access Control Model for Distributed Collaborative Editors

Distributed Collaborative Editors (DCE) provide computer support for modifying simultaneously shared documents, such as articles, wiki pages and programming source code, by dispersed users. Controlling access in such systems is still a challenging problem, as they need dynamic access changes and low latency access to shared documents. In this paper, we propose a Mandatory Access Control (MAC) based on replicating the shared document and its authorization policy at the local memory of each user. To deal with latency and dynamic access changes, we use an optimistic access control technique where enforcement of authorizations is retroactive. We show that naive coordination between updates of both copies can create security hole on the shared document by permitting illegal modification, or rejecting legal modification. Finally, we present a novel framework for managing authorizations in collaborative editing work which may be deployed easily on P2P networks

Flexible Concurrency Control for Real-Time Collaborative Editors

International audienceReal-time Collaborative Editors (RCE) provide computer support for modifying simultaneously shared documents, such as articles, wiki pages and programming source code, by dispersed users. Due to data replication, Operational Transformation (OT) is considered as the efficient and safe method for consistency maintenance in the literature of collaborative editors. Indeed, it is aimed at??ensuring copies convergence even though the users's updates are executed in any order on different copies. Unfortunately, existing OT algorithms often fail to achieve this objective. Moreover, these algorithms have limited scalability with the number of users as they use vector time stamps to enforce causality dependency. In this paper, we present a novel framework for managing collaborative editing work in a scalable and decentralized fashion. It may be deployed easily on P2P networks as it supports dynamic groups where users can leave and join at any time

Feature-based Product Modelling in a Collaborative Environment

Ph.DDOCTOR OF PHILOSOPH