This paper presents Lamina, a system for providing security and privacy to users in a public IoT space. Public IoT spaces, such as an IoT-enable retail store, have the potential to provide rich, targeted information and services to users within the environment. However, to fully realize such potential, users must be willing to share certain data regarding their habits and preferences with the public IoT spaces. To encourage users to share such information, we present Lamina, a system that ensures the user's data will not be leaked to third parties. Lamina uses CryptoCoP-based encryption and a unique MAC address rotation mechanism to ensure that a user's privacy is maintained and their data is protected while still allowing the public IoT space to collect sufficient information to effectively provide targeted services.