Method and management server for revoking group server identifiers of compromised group servers

摘要

Method and management server for revoking group server identifiers of compromised group servers. A management server determines an identity-based cryptographic signing key based on a group server identifier. This is distributed via the management server to a group server. The management server receives a security status indicating whether the security of the group server is compromised. If the security of the group server is compromised the management server then transmits a revocation of the group server identifier to the communication devices within that group. In particular the devices may operate in accordance with a Push-To-Talk specification. The management server may request a security status from a group server. The management server may also take corrective action if it is determined a group server is compromised.