Motorola MTP850 Ex - 12.3.4 Encryption Mobility; 12.3.5 Encryption MMI; 12.3.6 AIE Key Storage

Security Services 2-39
March 2009 Chapter 2 - MTP850 Ex/MTP810 Ex Product Information Manual 6866588D21-D
Benefits:
Benefits:
• Increased security, better protection of sensitive voice, data, identities and signalling
information.
• Regularly changing the keys makes the TETRA services more difficult to crack by potential
attackers.
• DCK is a new Key at each Authentication (Logon), and is never send “over air”.
• CCK is known to all Group members, and is changed daily.
• GCK is known to dedicated Group members, and is changed every 3 months by default.
12.3.4 Encryption Mobility
A Class 2 or Class 3 terminal will also be able to operate on a lower class SwMI if it is provisioned to
allow this. A terminal that is provisioned to not allow operation on a lower class SwMI, will not
register on such a cell.
A Class 2 or Class 3 terminal upon camping on a cell that supports an SCK/CCK/GCK that the
terminal possesses, will apply AI Encryption to the registration PDU. If no acknowledgement is
received, the terminal will then send the registration in clear.
12.3.5 Encryption MMI
A Class 2 or Class 3 terminal that is involved in a clear call, will provide a visual as well as an
audible indication to the user that the call is not encrypted.
12.3.6 AIE Key Storage
The terminal stores all the keys, SCK/CCK/DCK/GCK, in a sealed manner in non-volatile memory of
the terminal - but not in the codeplug.