Motorola MTM800 - 11.3.8 Interaction Network;Terminal - Encrypted;Clear; 11.4 End-to-End Encryption

Security Services 2-39
September 2008
Chapter 2 - MTM800 Product Information Manual 6866537D87-F
11.3.8 Interaction Network/Terminal - Encrypted/Clear
11.4 End-to-End Encryption
The TETRA standard supports encryption over the air. Air Interface Security is defined and specified
for TMO and for DMO, see Paragraph 11.3 "Air Interface Encryption (AIE)". The terminal creates the
PDU (Packet Data Unit) and the PDU is encrypted before transmission. The base station receives
this PDU and needs to decrypt it, to know what to do with it and where to send it. Thus, if a PDU
contains voice information, the voice part of the message has been decrypted and is now
unprotected, until it is transmitted out to the caller.
The End-to-End Encryption feature (E2E encryption) resolves this by encrypting the voice
information before it is packed into the PDU. The voice encryption is carried out by a Universal
Crypto Module (UCM), which takes the voice stream and encrypts this stream using a set of keys.
Likewise, the UCM takes encrypted voice stream and using the same keys decrypts back into clear
voice.
You are capable to make or receive E2E encrypted calls:
MR3.0 - Wi ll begin in encrypted
mode, operati ng correctly. When
the radio detect s f rom the system
broadcast that Encrypted Mode is
not supported, the radio will display
"Registration Failure" and thus
cannot operate.
MR2.1 and MR3.0 : Radi o switches to
clear after det ection of updated system
broadcast .
MR2.1 : same situation exists as in
"Constant Clear mode" in that once
registered, terminal will fail during
handover to other cells.
MR2.1 and MR3.0 : invalid scenario since
the radios only have Clear software - they
will never be in encrypted mode.
If however this scenario did occur,
typically the radios would have been in
"Registration Fail ure" so once system has
moved to Clear, terminal s could be reset
and they would succesfully r egister in
Clear mode.
Switch from
Encryted to
cl ear
MR3.0 Radio will register as normal
when switched to encryption - full
operation
MR2,1 : radi o will succesfully move to
Encrypted mode if it is still in operation in
Clear mode. If however the radio has
failed handover etc, the radio i s "locked
out" and will need to be reset to regain
operation on the encrypted network
MR3,0 : will succesfully switch to
encrypted mode after detection of the
secure network broadcast info.
MR2.1 and MR3.0 : Radio wil l not be able
to regi ster (as Encrypted) on system as it
only has Clear software. Radio wil l display
Registration Fai lure
Switch from
clear to
Encryted
MR3.0 Radio will register as normal
- full operation
MR2.1 and MR3.0 : Radi o works normallyMR2.1 and MR3.0 : Radio wil l not be able
to regi ster on system as it only has Clear
soft ware. Radio will di splay Regist ration
Fai lure
Constant
Encrypted
mo de
MR3.0 - the radio will detect from
the system broadcast that
Encrypted Mode is not supported
and thus cannot register.
Radio Display : tbc
Invalid Scenario. If the MR3.0
Encrypted Only flag is set then the
terminal CANNOT enter Clear mode
in any ci rcumstance. Thus, the
radio is always in Encrypted mode -
which is not possible with Clear
software - refer to the comments in
the next col umn
MR2.1 : when registering, terminal
detects system is in Clear mode and thus
will register in Clear mode. Radio wil l
operate normally within the cell which
registrat ion took place but will drop out
of service during handover. Radio will
typically display No Group. Recovery is
only achieved by turning radio On/ Off.
MR3.0 : when registering, radio will detect
system is in Clear mode and wi ll register
in Clear mode. All cal ls and operation
possible.
MR2.1 & MR3.0 : when registering, radio
will detect system is in Clear mode and
will register in Clear mode. All calls and
operation possible.
Constant Clear
Mo de
Encrypted Only Fl ag: set
(only applies to MR3.0)
Encrypted Only Flag: set
(only applies to MR3.0)
Encrypted Only Flag: not set
(only applies to MR3.0)
Encrypted Only Flag: not set
(onl y applies to MR3.0)Net wor k
Encrypted mode
(i.e. radio loaded with TEA2 SW)
Cl ear Mode
(i.e. radio loaded with Clear SW)
Encrypted mode
(i.e. radio loaded with TEA2 SW)
Cl ear Mode
(i.e. radio loaded with Clear SW)
Radi o
vs.
MR3.0 - Wi ll begin in encrypted
mode, operati ng correctly. When
the radio detect s f rom the system
broadcast that Encrypted Mode is
not supported, the radio will display
"Registration Failure" and thus
cannot operate.
MR2.1 and MR3.0 : Radi o switches to
clear after det ection of updated system
broadcast .
MR2.1 : same situation exists as in
"Constant Clear mode" in that once
registered, terminal will fail during
handover to other cells.
MR2.1 and MR3.0 : invalid scenario since
the radios only have Clear software - they
will never be in encrypted mode.
If however this scenario did occur,
typically the radios would have been in
"Registration Fail ure" so once system has
moved to Clear, terminal s could be reset
and they would succesfully r egister in
Clear mode.
Switch from
Encryted to
cl ear
MR3.0 Radio will register as normal
when switched to encryption - full
operation
MR2,1 : radi o will succesfully move to
Encrypted mode if it is still in operation in
Clear mode. If however the radio has
failed handover etc, the radio i s "locked
out" and will need to be reset to regain
operation on the encrypted network
MR3,0 : will succesfully switch to
encrypted mode after detection of the
secure network broadcast info.
MR2.1 and MR3.0 : Radio wil l not be able
to regi ster (as Encrypted) on system as it
only has Clear software. Radio wil l display
Registration Fai lure
Switch from
clear to
Encryted
MR3.0 Radio will register as normal
- full operation
MR2.1 and MR3.0 : Radi o works normallyMR2.1 and MR3.0 : Radio wil l not be able
to regi ster on system as it only has Clear
soft ware. Radio will di splay Regist ration
Fai lure
Constant
Encrypted
mo de
MR3.0 - the radio will detect from
the system broadcast that
Encrypted Mode is not supported
and thus cannot register.
Radio Display : tbc
Invalid Scenario. If the MR3.0
Encrypted Only flag is set then the
terminal CANNOT enter Clear mode
in any ci rcumstance. Thus, the
radio is always in Encrypted mode -
which is not possible with Clear
software - refer to the comments in
the next col umn
MR2.1 : when registering, terminal
detects system is in Clear mode and thus
will register in Clear mode. Radio wil l
operate normally within the cell which
registrat ion took place but will drop out
of service during handover. Radio will
typically display No Group. Recovery is
only achieved by turning radio On/ Off.
MR3.0 : when registering, radio will detect
system is in Clear mode and wi ll register
in Clear mode. All cal ls and operation
possible.
MR2.1 & MR3.0 : when registering, radio
will detect system is in Clear mode and
will register in Clear mode. All calls and
operation possible.
Constant Clear
Mo de
Encrypted Only Fl ag: set
(only applies to MR3.0)
Encrypted Only Flag: set
(only applies to MR3.0)
Encrypted Only Flag: not set
(only applies to MR3.0)
Encrypted Only Flag: not set
(onl y applies to MR3.0)Net wor k
Encrypted mode
(i.e. radio loaded with TEA2 SW)
Cl ear Mode
(i.e. radio loaded with Clear SW)
Encrypted mode
(i.e. radio loaded with TEA2 SW)
Cl ear Mode
(i.e. radio loaded with Clear SW)
Radi o
vs.