DEF CON 33 - RF Village - The dirty laundry of stored value washing cards - Aidan Nakache, Equip

This talk details a comprehensive reverse engineering analysis of stored-value laundry cards, prevalent in facilities worldwide. The widespread adoption of localised contactless payment solutions, attributed to their convenience, necessitates understanding their internal operations. This analysis explores the mechanisms behind value storage and modification within these cards. During this investigation, a data structure was identified that presented a significant vulnerability. The implications of this vulnerability raise serious concerns, which extend beyond laundry facilities, potentially impacting the security of similar contactless systems globally.