Case of study for in situ memory reading on damaged MultiMedia Card

Abstract

As the storage requirements of systems have increased, the evolution of data storage technologies has undergone a major shift. System manufacturers have recently switched from traditional flash technology to MultiMedia Cards (MMC), which are embedded memories with a dedicated controller. This technology allows for faster data transfer, greater reliability, and an increase in the storage capacity of a component as well as its lifespan. By design, the main weakness of these medium lies in the controller. If the controller fails to respond, the memory becomes unusable, which may negatively impact the user and the forensic expert who intends to retrieve essential data. The aim of the paper is to provide an overview of MMC technologies through their data transfer protocols. The main contribution is to share a diagnostic approach for extracting data from a flash chip controlled by a defective controller, based on the insights from a case study analysis. This work involves the study of the hardware conception of the MMC system as well as the reverse engineering and manipulations of the board with special equipment like X-Ray tomography, laser ablation, computer numerical control technology and logic analyzer.