A.2 Group key management

33.1793GPPRelease 13Security of Mission Critical Push To Talk (MCPTT) over LTETS

[33.179 MCPTT-A.2-001] Group key material shall be integrity and confidentiality protected for a specific MCPTT User during distribution from the MCPTT service to MCPTT UEs.

[33.179 MCPTT-A.2-002] Group key material shall be authenticated as coming from a valid, authorized source. The authorized source may be an MCPTT Administrator or may be another authorized entity (e.g. an authorized MCPTT User or Dispatcher).

[33.179 MCPTT-A.2-003] It shall be possible for authorized entities to dynamically create and distribute a new group security context at any time. This may be as part of a group creation process, be due to a periodic update to maintain key freshness, or due to compromise of group key material.

[33.179 MCPTT-A.2-004] The creation of a new group security context (e.g. via User-Regroup operation) shall not change or compromise an existing group security context.

[33.179 MCPTT-A.2-005] It shall be possible for an authorized, authenticated entity to revoke and update a group security context from use.