This document addresses the manual rekeying interface between a KFD and an MR only. Although some system level overview is provided, system level definition is not fully covered.

Purpose

This document describes the protocols, procedures, and features required for a manual rekeying function in an APCO Project 25 system. The manual rekeying function resides in a Key Fill Device (KFD) which interfaces to a Mobile Radio (MR).

Manual rekeying involves the exchange of Key Management Messages between a KFD and an MR for the purposes of provisioning an MR with encryption keys or other key management related information, erasing keys in an MR, or viewing key management related information in an MR. Manual rekeying can be used as the sole means for provisioning mobile radios with traffic encryption keys or it can be used in conjunction with OTAR rekeying procedures. When used with OTAR rekeying procedures, manual rekeying can be used to provision an MR with key management parameters required for OTAR operation in addition to provisioning encryp tion keys.

The manual rekeying function is a standard option with respect to the APCO project 25 standard. Within the manual rekeying standard option, some minimum set of features/ procedures are required and are considered mandatory while other features/procedures are not absolutely needed and are considered optional. This document defines all of the possible manual rekeying KFD features and procedures and designates which are mandatory and which are optional. At a minimum, an APCO Project 25 compliant KFD and MR should implement the mandatory set of features and procedures.