Over 2 million people across the United States are living with aphasia, the loss of language due to acquired brain injury. Aphasia is an invisible disability that may come with negative consequences for communication, community participation, and quality of life. Game-based rehabilitation is a promising solution to address unmet long-term recovery and psychosocial needs for people with aphasia. In this paper, we describe a participatory game design process that engages people with aphasia (PwA) in the creation of three hybrid digital-analog games. We detail methods for facilitating collaboration across language barriers and divergent professional expertise based on interviews and participant observations throughout our iterative design process. We also contribute a set of design principles synthesized from aphasia rehabilitation research, interviews and community data. We conclude with recommendations for pursuing community-empowered aphasia game design for this underserved population based on reflection from our co-design experience.

In this work, we put forward the notion of Worry-Free Encryption. This allows Alice to encrypt confidential information under Bob's public key and send it to him, without having to worry about whether Bob has the authority to actually access this information. This is done by encrypting the message under a hidden access policy that only allows Bob to decrypt if his credentials satisfy the policy. Our notion can be seen as a functional encryption scheme but in a public-key setting. As such, we are able to insist that even if the credential authority is corrupted, it should not be able to compromise the security of any honest user.