The present document contains a study of the security aspects of the Mission-Critical Push-To-Talk (MCPTT) service and its interaction with the network. This includes an analysis of the threats to the service, the security requirements to mitigate those threats and an evaluation of possible technical solutions designed to meet the security requirements of the service. The Stage 1 requirements for the service are defined in TS 22.179. An evaluation of Stage 2 architectural solutions for MCPTT is performed in TR 23.779 and TS 23.179. This study will include consideration of relevant 3GPP specifications, particularly for ProSe (TS 33.303, TS 23.303) and GCSE (TS 23.468). The focus of the present document is to support public-safety use cases of MCPTT. Commercial scenarios are not specifically considered and some features may not be applicable to them.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

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