Browse Prior Art Database

AUTOMATIC MANAGEMENT OF GROUPS OF TARGETS FOR OTAR PURPOSES

IP.com Disclosure Number: IPCOM000009571D
Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2002-Sep-03
Document File: 3 page(s) / 109K

Publishing Venue

Motorola

Related People

Mark Gonsalves: AUTHOR [+2]

Abstract

In order to have proper encrypted radio commu- nications, encryption keys need to be assigned to the targeted radios. This may be done using OTAR (Over The Air Rekey) where keys are first assigned to the targeted units using a KMF (Key Management Facility), following which they are transmitted over the air in data packets using a pre- defined protocol.

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MOTOROLA Technical Developments

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AUTOMATIC MANAGEMENT OF GROUPS OF TARGETS FOR OTAR PURPOSES

by Mark Gonsalves and David Larson

BACKGROUND

  In order to have proper encrypted radio commu- nications, encryption keys need to be assigned to the targeted radios. This may be done using OTAR (Over The Air Rekey) where keys are first assigned to the targeted units using a KMF (Key Management Facility), following which they are transmitted over the air in data packets using a pre- defined protocol.

  During OTAR delivery to single target unit, the encryption key information is sent encrypted using a UKEK (Unique Key Encryption Key) and routed using an individual RSI (Radio Set Identifier). When a group of units have the same encryption information assigned, this delivery may be accom- plished in a more efficient manner using group OTAR. In this case the encryption information is broadcast encrypted using a CKEK (Common Key Encryption Key) residing in all the units targeted and have a group RSI assigned within the units for routing.

  The challenge is to identify the units that have similar encryption information and provide them with a CKEK and group RSI so that they can receive these group messages, decrypt and process

them.

  The obvious way to accomplish the above is to manually create the groups within the KMF and pro- vide these groups with CKEKs and group RSIs. However, this adds burden on the KMF operator to identify units that belong to a group and added over- head of managing these groups.

  This happens when the encryption information of a few units within a group change and have to be reassigned to other groups or a new group and a new CKEK and group RSI assigned to the group they left so that the removed units will not get inadver- tently targeted when sending OTAR messag...