: Designing to Support Digital Privacy with Shared Mobile Phone Use in Bangladesh

People in South Asia frequently share a single device among multiple individuals, resulting in digital privacy challenges. This paper explores a design concept that aims to mitigate some of these challenges through a 'tiered' privacy model. Using this model, a person creates a 'shared' account that contains data they are willing to share and that is assigned a password that will be shared. Simultaneously, they create a separate 'secret' account that contains data they prefer to keep secret and that uses a password they do not share with anyone. When a friend or family member asks to check their device, the user can tell them the password for their shared account, with their private data secure in the secret account that the other person is unaware of. We explore the benefits and trade-offs of our design through a three-week deployment with 21 participants in Bangladesh, presenting findings that show how our work aids digital privacy while also exposing the challenges that remain.