ACCORD: Constraint-driven mediation of multi-user conflicts in cloud services


When multiple users adopt collaborative cloud services like Google Drive to work on a shared resource, incorrect or missing permissions may cause conflicting or inconsistent access or use privileges. These issues (or conflicts) compromise resources confidentiality, integrity, or availability leading to a lack of trust in cloud services. An example conflict is when a user with editor permissions changes the permissions on a shared resource without consent from the original resource owner. In this demonstration, we introduce ACCORD, a web application built on top of Google Drive able to detect and resolve multi-user conflicts. ACCORD employs a simulator to help users preemptively identify potential conflicts and assists them in defining action constraints. Using these constraints, ACCORD can automatically detect and resolve any future conflicts.

WWW 2024