To position LTE as technology for critical communications such as public safety, security for Group Communication (GC) needs to be considered. Group Communication function complements its sibling communication feature of Proximity-based Services (ProSe).

The present document studies the security aspects of the Group Communication Service Enabler for LTE (GCSE_LTE) and gives an evaluation of possible technical security solutions supporting such an Enabler. The present document looks at security from system perspective and defines functional security requirements for all entities. Stage 1 requirements for these services are defined in TS 22.468. Different possible Stage 2 solutions for GCSE have been studied in TR 23.768. 3GPP TS 23.468 provides the stage 2 description for the 3GPP system provided enablers to support GC services using E-UTRAN in Rel-12. Based on the work done in TS 22.468, TR 23.768, and TS 23.468 the objectives of the present document are to identify the threats and deduce security requirements, develop GCSE_LTE security solutions, and determine which solution(s) from the present document (Study/TR phase) should be converted into normative specifications for Rel-12.

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

• References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.