In this work we present a solution for real-time dynamic security features in ProSe. Levels of security are defined and mapped with different security objectives to protect packets. The levels are linked to different ProSe operating modes and packet types. A method with minimal radio cost and security overhead is then proposed that allows changes in security levels in real-time. A list of security parameters is designed that serves as the security policy in the Core Network and is enforced in the User Equipments through their bootstrapping. A security payload for MIKEY is built with the list of parameters. The solution is totally compatible with both ProSe and MIKEY standards.