Philips Pnvx 6318 User Manual

SECURE TELEPHONE SET

PNVX 6318

SYSTEM DESCRIPTION

Philips
Crypto B.V.

PHILIPS

PHILIPS

SECURE TELEPHONE SET

SECURE TELEPHONE SET

SYSTEM DESCRIPTION

PNVX 6318

SYSTEM DESCRIPTION

Philips Crypto B. V.

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

Philips Crypto B. V.

Document No. 9922 154 19463

• Philips Crypto B.V. 1995
All rights reserved

This document is classified commercial in confidence.
It may not be reproduced wholly or partly in any way,
or shown to a third party, without prior permission
from Philips Crypto B.V.

Subject to modification without prior notice.

Printed in The Netherlands

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

C O N T E N T S P a g e

1 I N T R O D U C T I O N 1

2 S P E C I F I C A T I O N S 2

2 . 1 C r y p t o g r a p h i c s p e c i fi c a t i o n 2

2.2 Electrical specification 2
2 . 2 . 1 E l e c t r i c a l s i g n a l s 2
2 . 2 . 2 B a t t e r y b a c k u p 3

2 . 2 . 3 P o w e r s u p p l y 3

2.3 Mechanical specification 3
2 . 4 N u m b e r s t o r e 4
2 . 5 E n v i r o n m e n t a l c o n d i t i o n s 5

2 . 5 . 1 C l i m a t i c 5

2.5.2 Mechanical 5
2 . 6 S a f e t y 5
2 . 7 T e s t s a n d s e r v i c e a b i l i t y 5

2 . 8 R e l i a b i l i t y 5

2.9 Sealing 6
2 . 1 0 C o m p o s i t i o n , t y p e n u m b e r s a n d a c c e s s o r i e s 6

3 T E C H N I C A L D E S C R I P T I O N 6

3.1 General 7

3.2 Working 8

3.2.1 Introduction 8

3 . 2 . 2 F u n c t i o n a l p a r t s o f b l o c k d i a g r a m 8

3.2.3 Survey of operational situations of the Secure Telephone Set 15

4 O P E R A T I O N 1 7

5 G L O S S A R Y O F T E R M S A N D A B B R E V I A T I O N S 2 1

ILLUSTRATIONS

F i g . 1 : P h i l i p s S e c u r e T e l e p h o n e S e t P N V X 6 3 1 8 1
F i g . 2 : S e c u r e T e l e p h o n e S e t : d i m e n s i o n s 4
F i g . 3 : S e c u r e T e l e p h o n e S e t : s i m p l i fi e d b l o c k d i a g r a m 7
Fig. 4: Secure Telephone Set: firmware control 9
Fig. 5: RS232-C/CCITT V.24 interface 11
F i g . 6 : K e y C a r d I n t e r f a c e : b l o c k d i a g r a m 1 2
F i g . 7 : S u r v e y o f s y n c h r o n i s a t i o n / r e s y n c h r o n i s a t i o n 1 3
F i g . 8 : S u r v e y o f o p e r a t i o n a l s i t u a t i o n s 1 5
F i g . 9 : S e c u r e T e l e p h o n e S e t : b l o c k d i a g r a m 1 6
F i g . 1 0 : S e c u r e T e l e p h o n e S e t : c o n t r o l s 1 7

Fig. 11: Keypad layout 20

P h i l i p s C r y p t o B . V . / / /

SECURE TELEPHONE SET SYSTEM DESCRIPTION

INTRODUCTION

The Philips Secure Telephone Set PNVX 6318 is a standard telephone apparatus with an

integrated high-grade digital crypto unit. It is the successor of the PNVX 6317 and offers a

better speech quality due to the incorporation of higher speed modems in combinations with
more sophisticated vocoder techniques.

With the PNVX 6318 it is possible to achieve both secure and normal operation via the public
switched telephone network.

The apparatus has three full-duplex communication modes, namely:

- non-encrypted speech (normal telephone operation);

- encrypted speech;

- encrypted data (in accordance with V.24/RS232-C).

The Secure Telephone Set is provided with a Key Card Reader. Operation in the crypto mode
is possible only after a valid Personal Key Card (smart card °) has been inserted and the valid
Personal Identification Number (PIN code) associated with that specific card has been keyed in.

The Secure Telephone Set is intended for desktop use, and is fully interoperable with the
PNVX 6317 (2400 bit/s-mode).

Fig. 1: Philips Secure Telephone Set PNVX 6318

'} InnovatronS.A. Licence

Philips Crypto B. V.

SECURE TELEPHONE SET

2 S PE C I FI C AT I ON S

2.1 Cryptographic specification

The cryptographic specification is classified information and can be obtained on request at the
NLNCSA.

2.2 Electrical specification

2.2.1 Electrical signals

• Line connection In accordance with the requirements of the Netherlands PTT
laid down in T10-T11.

SYSTEM DESCRIPTION

• Dial modes

Line signals during
crypto operation

Data terminal
connection

• Monitor connection
(recorder)

Analog-digital
conversion

Pulse dialling or tone dialling, selected via the program
function of the apparatus (menu).

- 9600 bit/s full duplex in accordance with CCITT - V.32

- 4800 bit/s full duplex in accordance with CCITT - V.32

- 2400 bit/s full duplex in accordance with CCITT - V.22bis

(interoperable with PNVX 6317)

- In accordance with EIA - RS232-C / CCITT - V.24

- Bit rates:
. 9600 bit/s synchronous (< 2400 bit/s asynchronous 2))

. 4800 bit/s synchronous (< 1200 bit/s asynchronous 2))
. 2400 bit/s synchronous (< 600 bit/s asynchronous 2))

(interoperable with PNVX 6317)

Analog telephone signal:

- output: 150 mV (unloaded) at 50 mV-eff, 800 Hz, on

microphone of handset

- impedance: 150 fl

- By means of a CELP vocoder (9600 bit/s or 4800 bit/s) or
an LPC-10 vocoder (2400 bit/s)

- Intelligibility (IZF 1982-13), back-to-back
. at 9600 bit/s

. at 4800 bit/s
. at 2400 bit/s

> 95 % DRT
> 92 % DRT

> 83 % DRT

21 Higher rates are available if the async/sync converter option is chosen.

Philips Crypto B.V.

SECURE TELEPHONE SET

SYSTEM DESCRIPTION

Loudspeaker signal

2.2.2 Battery backup

The Secure Telephone Set is provided with a battery to protect the contents of the RAM when
the power supply is disconnected.

Protection with battery

2.2.3 Power supply

• Voltage (DC) 8.0 V ± 5 % or 12.0 V (-2.5 V/ + 3,5 V)

• C o n s u m p t i o n M a x . 1 2 W

- Ringing signal: volume adjustable via the program function

of the apparatus (menu).

- Speech signal volume: max. 200 mW, adjustable with

potentiometer to - 20 dB

- Warning signals:
. when switching from plain to CRYPTO and vice versa.

. when switching from VOICE to data and vice versa.
. when an operator error occurs.

±10 years

An external 8 V power supply unit is available as an accessory.

2.3 Mechanical specification

• Dimensions (in mm) 282 x 248 x 113 (w x d x h, see Fig. 2)

• W e i g h t 2 . 7 k g a p p r o x .

• Material of housing

• Power supply connector

• Connector for handset

• Data connector

• Connector for line cable
(apparatus side)

• Connector for monitor
outlet

- top: synthetic

- bottom: metal

Amphenol T3362-100 male receptacle 5 pole

4-wire, 4-pole

D-connector female 25 pole

4-wire, 6-pole

Typ e CIN CH

Philips Crypto B. V.

SECURE TELEPHONE SET

Pushbuttons 12 numeric pushbuttons: 0...9, * and #

SYSTEM DESCRIPTION

6 function pushbuttons:

DATA, CRYPTO, PLAIN, LSP, MUTE and MODEM

4 selection pushbuttons:

< (reset, double function),

dial, mem and R
4 program pushbuttons:

< (reset, double function),

enter, menu, i (scroll down) and t (scroll up).

Fig. 2: Secure Telephone Set: dimensions

• Display

• Key Card Reader

• Memo plates

2.4 Number store

The Secure Telephone Set is provided with a subscriber memory based on numbers.

Subscriber memory

based on numbers

LCD display with 2 x 24 alphanumeric characters

Built in for communication with the Personal Key Card

- In the base; pull-out tray, with room for telephone numbers
and corresponding names.

- Under handset: plate for own number

30 memory compartments

numeric keypad (see Fig. 11)

Philips Crypto B.V.

SECURE TELEPHONE SET

2.5 Environmental conditions

2.5.1 Climatic

SYSTEM DESCRIPTION

• Temperature during

operation

• Temperature during

transport/storage

2.5.2 Mechanical

• Vibration resistance

• Drop resistance

2.6 Safety

• Safety class

+ 5°C to + 50°C (except display: guaranteed up to + 35 °C)

- 25°Cto + 70°C

IEC 68-2-6, test Fc

IEC 68-2-32, test Ed

Apparatus meets the requirements of EN 60-950, class II type

B, with regard to:

- electrical contact safety

- short circuit

- combustibility

- mechanical safety

- radiation

- chemical gases and vapours

2. 7 Te s ts an d ser vi ce abi l ity

• Self-test

• Usability test

• Diagnostic tests

• MTTR

• Modular set-up

2.8 Reliability

• MTBF

Automatic test of the functional working when the apparatus is
first switched on

Test to be carried out by operator via the menu in order to
ascertain whether the apparatus functions well

Tests on modules and interfaces

< 30 minutes

Number of exchangeable modules: 6

- digital circuit

- analogue circuit

- crypto kernel

- top cover

- handset

- filter unit

> 15,000 hours

Philips Crypto B.V.

SECURE TELEPHONE SET SYSTEM DESCRIPTION

2.9 Sealing

The Secure Telephone Set is provided with a seal which will be irreparably damaged if the
apparatus is opened.

2.10 Composition, type numbe r s and accessories

• Composition

Typ e numb er s

The Secure Telephone Set consists of the following parts:

- telephone set;

- handset with cable;

- packaging;

- operating instructions.

The Secure Telephone Set is fitted with a type plate bearing
the following text:

Philips Crypto B.V.
Made in Holland

Ty pe U P 63 1 8/X X ( z z) |
N C 9 9 2 2 4 1 6 3 1 8 x x !

N o c c c c d d d d !

INNOVATRON S.A. Licence

8.0 V

1.4 A

xx = version number (01 - 99)
cccc = serial number
dddd = week of production
zz = country code in accordance with UN-D 1157

Accessories

The following accessories are available:

- 8.0 V DC power supply unit;

- Line cable.

- Async/sync converter

Philips Crypto B. V.

SECURE TELEPHONE SET

3 TE CHNI CA L DES CR IP TI ON

3.1 General

The Philips Secure Telephone Set is a standard telephone apparatus with a built-in high-grade
crypto unit.

This crypto unit makes use of digital encryption. For that purpose the apparatus is provided
with the means of converting the analog telephone signal into a digital signal and vice versa.

Full-duplex information transfer with a bit rate of 9600 bit/s, 4800 bit/s and 2400 bit/s can be

chosen, using a V32 or V22bis modem.

To obtain a speech transfer of good (fair) quality with these, relatively low, bit rates, two types
of speech coders are used; a CELP vocoder for the bit rates 9600 bit/s and 4800 bit/s and an
LPC-10 vocoder for the bit rate 2400 bit/s.

SYSTEM DESCRIPTION

Because the digital information produced by the crypto unit cannot be transmitted in that form,
the built-in modem converts the digital signal into an analog signal which is suitable for
transmission via the narrow-band (300 - 3400 Hz) Public Switched Telephone Network

(PSTN). At the same time (full-duplex), this modem recovers the original digital signal

encrypted at the other end of the link and offers it to the crypto unit for decryption.

MI C c — o

TEL

DATA o-

VOCODER

(CELP/
LPC-10)

V.24/
RS232-C

INTERFACE

L

o

-o | o-*­CRYPTO

UNIT

MODEM

IH

T- Z

J

LINE

INTER
FACE

—o LINE

Fig. 3: Secure Telephone Set: simplified block diagram

Philips Crypto B.V.

o PLAIN
o CRYPTO VOICE
O CRYPTO DATA

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

3. 2 Wo rk ing

3.2.1 Introduction

The functional description in the following paragraphs is based on the more detailed block
diagram (Fig. 9 - see last page of this part). The most important functional parts of the block

diagram are described.

Following this, Figure 8 gives a survey of the operational states of the Secure Telephone Set
and shows the possible transitions resulting from operation and control commands.

3.2.2 Functional parts of block diagram (see Fig. 9)

■ System processor

The System Processor has full control of the Secure Telephone Set. This includes the control of
the functional units and the digital data flow, and also the initiation of tests (BITs) in the
various units.

Hardware

The System Processor is connected with all essential parts of the apparatus via a bus system.

Although the data flow reproduced in the block diagram (Fig. 9) has been correctly indicated
from a functional point of view, it must be appreciated that the practical realisation of the data
flow is slightly different, because all digital commands are transmitted via the common bus

system controlled by the System Processor.
The System Processor consists of an 80C528-microprocessor, an EPROM, an EEPROM, a

RAM and several ICs for decoding and buffering.

Firmware

The System Processor is controlled by the firmware. In the firmware not only are the various
functions laid down (e.g. authorisation of the user, identification, key selection, etc.), but also

the control and the selection of the various hardware parts.
For instance, the dialling information entered by the user via the pushbuttons is first read by the
firmware and then passed on to the line.

The firmware control is shown schematically in Fig. 4.

■ Analog circuit

The analog circuit forms the interface between the handset, the hands-free microphone, the
loudspeaker control, the monitor outlet, the analog in-/output of the PCM circuit and the plain

switch.

The circuit contains three amplifiers. Two of these are used for the amplification/adaptation of

the microphone and telephone signal; the third is used for the amplification/adaptation of the

monitor signal.

Philips Crypto B. V.

SECURE TELEPHONE SET

SYSTEM DESCRIPTION

SWITCHES

ALARM

Presence

RS232/V.24

Data

Command

Audio route

(Plain/Handsfree/

Dial)

Al a rm In t err u pt

Card

Card
Command

Card

J L

KEY CARD KEYBOARD

Response

Voice

Command

VOCODER CRYPTO UNIT

t—i—r

Plain-

Message

Line Command MODEM

FIRMWARE

Dia l D i g i ts

Line Control

Matrix

Code

-Crypto

_L_

DISPLAY

Message

-Crypto
Commands

Display
command

LINE INTERF.

Fig. 4: Secure Telephone Set: firmware control

■ Hands-free circuit

This circuit, which is part of the analog circuit, uses the 'voice switching' principle; a half­duplex connection is set up when the Hands-free function is in use, and the level of the

microphone signal determines whether the microphone or the loudspeaker is switched on (i.e.
whoever is speaking gets the line).

■ Plain switch

The switch-over from plain to crypto, and vice versa, is accomplished with the help of different
types of analog multiplexers controlled by the System Processor.

■ PCM circuit

A/D conversion

In the A/D converter of the PCM circuit, the analog signal from the microphone is converted

into digital information in accordance with the pulse code modulation principle (Linear);
conversion takes place at a sampling frequency of 8 kHz. The digital output consists of 16-bit

words, which are transferred serially to the inlet of the Digital Signal Processor (DSP).

Philips Crypto B. V.

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

D/A conversion

The digital information from the DSP is transferred to the D/A converter of the PCM circuit,
where it is converted into an analog signal.

■ Digital Signal Processor

The Digital Signal Processor (DSP) has two vocoder functions:

- converting the digital information received from the PCM circuit to a digital stream of data

(and vice versa) according to the CELP principle (CELP = Code Excited Linear Prediction);

- converting the digital information received from the PCM circuit to a digital stream of data

(and vice versa) according to the LPC-10 principle (LPC = Linear Predictive Coding).

The firmware determines which of the two principles will be chosen. For the bit rates
9600 bit/s and 4800 bit/s the CELP principle will be chosen. When a bit rate of 2400 bit/s is

required the LPC-10 principle will be chosen. When interoperability with a Secure Telephone
Set of type PNVX 6317 is required the firmware will choose always the LPC-10 principle.

CELP vocoder

Transmitting end:
Frames of 240 samples from the A/D converter are temporarily stored in a speech buffer.

Every 30 ms a frame is converted into several speech parameters. These parameters contain
such information as quantified LPC filter coefficients. In order to minimise the effects of

transmission errors on bad lines, the most important speech parameters are protected using an
error correction code. The channel coding technique used provides stronger protection for the
most significant bits of these speech parameters. Interleaving is applied to randomise burst
errors and the resulting frame data is transferred to the crypto unit.

Receiving end:
After de-interleaving, error correction is carried out making use of the line quality information

from the modem. Under adverse transmission conditions some speech parameters may be badly
corrupted, this loss of data is concealed by repeating previous good values. The resulting set of

speech parameters are used to synthesise the output speech wave form which is then transferred
to the D/A converter.

LPC-10 vocoder

Transmitting end:
Frames of 180 samples are temporarily stored in a buffer. Every 22.5 ms LPC and pitch

analysis are carried out. The latter is performed using a DFT based harmonic sieve. The
resulting 54 bit data frame, formatted according to STANAG 4198 is transferred to the crypto

unit.

Receiving end:
Every 22.5 ms the crypto unit transfers the received data frame to the DSP. During unvoiced

frames forward error correcting Hamming codes are used to detect the amount of errors on the

channel and to form an estimate of the bit error rate (BER). Depending on the BER estimate
the speech parameters including the pitch are smoothed, thus concealing the channel errors. The
corrected and smoothed data are then used to synthesise the 180 samples of output speech

which are transferred to the D/A converter.

P h i l i p s C r y p t o B . V . 1 0

SECURE TELEPHONE SET SYSTEM DESCRIPTION

■ Data/voice switch

The firmware determines which of two sources (DSP or data connection) will be enabled. The

data from the enabled source is passed on to the crypto unit.

■ RS232-C/V.24 interface

This circuit (see Fig. 5) takes care of the interface between the terminal connection and the bus

system (signals/levels are in accordance with V.24/V.28, CCITT).

The input signals are converted to HCMOS-level by level- converter 1 (receiver); the output

signals are converted to the right level by level converter 2 (driver).

D-connector

T

103

105 o

108 o

107

106

104 o—<—

115 o—<—

114 o—«—

109 o—«—

102 o

101

°TL

LEVEL
CONV.

(1)

-\ SYSTEM

-/ PROCESSOR

LEVEL

CONV.

(2)

j_L

HF-radiation protection

cct

pin

meaning

103 2 Data Input
105 4

108 20 Data Terminal Ready

107 6 Data Set Ready
106 5 Clear To Send
104 3 Data Output
115 17 Receive Clock
114 15 Transmit Clock
109 8 Carrier Dete ct
102 7
101 1 Protection Ground (case)

Request To Send

Digital Ground (on PCB)

Fig. 5: RS232-C/CCUT V.24 interface

■ Key Card interface

The Key Card interface detects the presence of the Personal Key Card and makes possible the
interchange of Identification Code and key information between the apparatus and the card. The

correctness of the Identification Code entered by the user is checked by the Personal Key Card.

Philips Crypto B. V.

11

SECURE TELEPHONE SET SYSTEM DESCRIPTION

KEY CARD
CONNECTOR

-o Vcc

-o Vpp

PKC

-o GND

-o CLK

-o RST

-o I/O

o o

/

KEY
CARD

INTERFACE

-\ SYSTEM

-/ PROCESSOR

Fig. 6: Key Card Interface: block diagram

■ Crypto unit

General

The cryptographic circuit is implemented as an independent encryption/decryption unit.

Presentation of the input, communication with the Personal Key Card, and the further
processing of the output, are governed by the System Processor. The correctness of the

Identification Code entered by the user is checked by the Key Card.

Encryption/decryption

Encryption and decryption is achieved by means of the stream cipher technique, in which a
pseudo-random bitstream produced by a keystream generator is continuously mixed with the

stream of digital data presented. To protect against active eavesdropping (i.e. hostile
manipulation of the cipher text) and hence to protect the integrity of the transmitted data, a

keystream-dependent non-linear mixing principle is employed.

The pseudo-random bitstream produced by the keystream generator consists of a sequence of

keybits which depends upon the session key and the synchronisation information bits (message

key).

The keystream generator is designed in accordance with the latest cryptographic principles and

is based on Philips Crypto B.V's extensive expertise. Aspects such as key diversity, sequence

complexity and various methods of attack have been taken fully into consideration.

Authentication

When a connection is established the Secure Telephone Set is in the PLAIN VOICE mode. The
transition to the CRYPTO VOICE mode is initiated by pressing the CRYPTO button. Transition
to the CRYPTO DATA mode is initiated by pressing the data button.

A Peer Entity Authentication Protocol is exchanged between both crypto units for identity

check, key selection and authentication before communication in crypto can be established.

User Identification

The identity of each user (Key Card) known by the input of the correct Identification-code
(access control) is coded and sent to the other party.

Philips Crypto B. V.

12

SECURE TELEPHONE SET SYSTEM DESCRIPTION

Key selection
If the identity of the other party is recognised and valid, each telephone set will retrieve (and

decrypt) the pairwise unique key information from its Key Card.

Peer Entity Authentication
A 'signature' calculated and coded by each party on basis of the pairwise unique key is sent to
the other party.
The verification of the signature received will guarantee the integrity of the other party (i.e. the
identified other party uses indeed the correct key).

Session key and synchronisation

When the authentication protocol is run through successfully both crypto units determine the

'session key'. Crypto synchronisation of the receiver is achieved by using the synchronisation

information bits received from the other party.

When synchronisation is achieved, both telephone sets adopt the CRYPTO VOICE (CRYPTO

DATA) mode. They can both be returned to the PLAIN mode by pressing the plain button.

Resynchronisation

Once both parties have been synchronised, it may subsequently become necessary to

synchronise again. In that case only synchronisation patterns are transmitted/received.

"CRYPTO" "DATA"

"CRYPTO" "DATA"

= authen ticatio n, key select ion and synch ronis ation

= res ynchronisation

Fig. 7: Survey of synchronisationlresynchronisation

Resynchronisation takes place in the following cases:

• if the crypto button is pressed during 'Crypto Voice' (to regain synchronisation after
disturbance of the line synchronisation)

• if the data button is pressed during 'Crypto Voice', as a consequence of which the

apparatus switches over to 'Crypto Data';

• if the crypto button is pressed during 'Crypto Data', as a consequence of which the

apparatus switches over to 'Crypto Voice';

Philips Crypto B. V. 13

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

• if the data button is pressed during 'Crypto Data' (to regain synchronisation after
disturbance of the line synchronisation).

• automatically during 'Crypto voice', if 'out of sync' is detected.

• after line signal interruptions (not more than 30 seconds). At 2400 bit/s not only a crypto
resynchronisation but also a modem resynchronisation takes place.

■ Modem

The modem converts the digital information presented (crypto-voice or crypto-data) into analog
signals suitable for the line, and vice versa.

During transmission the analog signal (carrier wave) is modulated with the digital signal
supplied from the crypto unit.

The digital signal transmitted by the other party is regained (demodulation) from the received
(analog) line signal and offered to the crypto unit for decryption. In this way the modem is

capable of processing full-duplex data at the chosen bit rate.

■ Dial circuit

This circuit receives the dialling information via the System Processor.
The circuit which is provided with anti-bounce measures, codes the pressing of a key into the
associated pulse or tone code and switches off the telephone/microphone signal route during

dialling (mute).

■ DC/DC-separation

Because the line interface circuit is fed from the line and the other circuits from the power
supply unit of the Secure Telephone Set, DC/DC-separation is incorporated; relays,

transformers and opto-couplers are applied at the points concerned.

■ Line interface

The universal line interface arranges the transfer of the analog signals from the Secure
Telephone Set to the public switched telephone network and vice versa.

This circuit also contains the hook relay, which is controlled by the hook contact signal
received from the System Processor.

■ Ringing signal detector

The ringing signal detector generates a control signal when the ringing signal is received from
the line. This control signal is transferred to the System Processor, which generates an
adjustable acoustic signal for the loudspeaker.

■ Recall circuit

When the R button is pressed (and the 'enable enquiry' facility is installed), the line connections
('a' and 'b') are connected to E. If the 'register recall' facility is installed, pressing the R button

will interrupt the line current for approx. 100 ms.

■ DC/DC converters

The built-in DC/DC converters supply the required DC voltages. The input voltage for these
converters is derived from an external DC power supply unit via a connector incorporated in
the housing.

P h i l i p s C r y p t o B . V . 1 4

SECURE TELEPHONE SET SYSTEM DESCRIPTION

The required DC input voltage is 8 V.

The DC/DC converters supply the following output voltages: +5 V, -5 V, +24 V and +7 V.

3.2.3 Survey of operational situations of the Secure Telephone Set

«POWER 0N»

POWER OFF INITIALISATION

+

INTERNAL TEST

«MENU»

I—<- MENU PRE-DIALLING

«ON HOOK» a «OFF HOOK» ▼ KEY CARD

DIALLING

«D ATA» or |

«CRYPTO» ▼ [«SYNC DETECT»]t

\ , , l _

TX PROTOCOLS RX PROTOCOLS

TX SYNC

«CRYPTO»

or

«DATA»

ON HOOK / STAND BY

Jm

PLAIN VOICE

RX SYNC

[resi

▼ detect]a a

KEY CARD
CONTROL

CONTROL

cnc

CRYPTO VOICE or
CRYPTO DATA

«ON HOOK»

(crypto voice only)

«PLAIN» ▼ received]

«...» = by operation

[...] = by control signal

Fig. 8: Survey of operational situations

[message "plain"

Philips Crypto B.V.

15

pulse dial

SWITCH

DIAL/PLAIN/CRYPTO

0 E

LINE

LINE

INTERF.

RING.

CIRC.

DC/DC separation

do •

p o—o

PLAIN SWITCH »

parts

u n d er c on tr ol

L2

CLOCK CIRCUIT

HOOK SWITCH

UNIT

CRYPTO

SWITCH

VOICE/ |—▶-

DATA

l_

1 GND

-▶ 4 7 V

♦ « p ar t u nde r co nt rol of t he S ys tem Pr oce ss or

oc » o pt o -c ou p l e r

t r - t ra n sf o rm e r

r el = r el a i s

PKC » Perso nal K ey Card

PLAIN

SWITCH

ANALOG

MIC

CIRCUIT

TEL

MON

HANDS ♦

MIC

FREE

LSP

RS232-C ♦

V.2 4

INTERFACE

KEY CARD ♦

INTERFACE

DC/DC

CONVERTER

2

S3

I

SI

f

3

SECURE TELEPHONE SET

OPERATION

The Secure Telephone Set has the following operational facilities:

Key Card Reader

Before the Secure Telephone Set can be used for crypto operation, the apparatus must be

provided with a valid Personal Key Card, which must be inserted into a slot on the right-hand

side of the Secure Telephone Set. The correct Personal Identification Code for that Key Card
must then be keyed in.

SYSTEM DESCRIPTION

1 H a n d s e t

2 P r o g r am p us h b ut t o ns
3 D i s p l a y
4 Disp l a y c o n t r a st control

5 K e yc ar d r ea de r

Numerical pushbuttons

By means of the numerical pushbuttons 0 ... 9, * and #, it is possible to enter a subscriber
number, to enter the required Personal Identification Code, to select a number from the
subscriber number store, to enter a new number into the number store or to note a subscriber
number during a conversation (MEMO function).

Philips Crypto B. V.

6 Personal Key Card
7 Memo plate

8

Loudspeaker volume control

9

Facility and Function keys

10 Numerals

Fig. 10: Secure Telephone Set: controls

17

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

Function pushbuttons

The function pushbuttons are: CRYPTO, PLAIN, DATA, LSP, mute and MODEM.

The CRYPTO button is used to switch over from plain-voice or crypto-data mode to crypto-voice
mode.

The PLAIN button is used to switch over from crypto-voice or crypto-data mode to plain-voice
mode.

The data button is used to switch over from plain-voice or crypto-voice mode to crypto-data
transmission via the RS232-C connection. By means of the crypto button switching over from

crypto data to crypto-voice is possible.
The 'hands-free' function is switched on (handset is on-hook) by pressing the LSP button. This

switches the apparatus off-hook and switches on the built-in loudspeaker and special
microphone. The 'hands-free' function is also activated in the plain-voice or crypto-voice mode

when the handset is replaced while the LSP button is pressed.
The 'hands-free' function is cancelled, and the on/off-hook function taken over by the hook

contact, by pressing the LSP button once again.

Pressing the LSP button in plain-voice mode (handset off-hook) switches on the built-in
loudspeaker. The 'loudspeaking' function is cancelled again by pressing the LSP button again.

Replacing the handset with 'loudspeaking' function switched on and pressing the LSP button
enables the 'handsfree' function.

Pressing the mute button suppresses the microphone signal; the situation is restored by
pressing the mute button again.

The modem button is used to change the modem startup speed. The modem startup speed can
be changed in plain-voice mode or when the handset is on-hook. The modem button is also
used to change the bit rate in crypto-voice and crypto-data mode.

Selection pushbuttons

The < button is used to erase display information during the telephony function.

The dial button initiates a call to the subscriber number shown in the display (also REDIAL­function).

Pressing the mem button makes it possible to initiate a call to one of the pre-programmed
subscriber numbers.

By means of the R button - and in plain-voice mode only - a conversation with someone else
can be started and finished, provided that this facility is supported by the local switched

telephone network and installed via the ENABLE ENQUIRY menu option.
The R button can also be programmed via the menu as REGISTER RECALL if this facility is

supported by the local switched telephone network.

Program pushbuttons

Via the program buttons menu, I (scroll down), t (scroll up) and ENTER, the user has access
to the menu facilities, such as: storing and changing subscriber numbers, changing (software)

settings, and carrying out the (internal) off-line diagnosis tests or the user test.
Some menu facilities can be used only when the Key Card has been inserted and the associated

Personal Identification Code has been accepted.

P h i l i p s C r y p t o B . V . 1 8

S E C U R E T E L E P H O N E S E T S Y S T E M D E S C R I P T I O N

Zeroize

All key material present in the PNVX (i.e. the red key material stored in the RAM) will be
erased when the crypto and ■* keys are pressed simultaneously. As a result, the

apparatus and the inserted Key Card are rendered unusable for all crypto functions. The crypto
functions of the apparatus can only be put back into service following a complete crypto

installation procedure. A zeroized Key Card can be programmed again.
Zeroizing is possible only if the zeroize function is made available during crypto installation.

On hook/off hook switch

The Secure Telephone Set has the usual hook contact.

Auto-answer facility

The PNVX 6318 will automatically set up a crypto data connection after detection of an
incoming call on the condition that the auto-answer mode has been enabled via the menu.

Display

The display contains two lines of 24 characters.

The upper line (state line) gives information with regard to the state of the Secure Telephone

Set, e.g. I plain voice 4.8 | is displayed when the apparatus is functioning as a normal
telephone (i.e. when speech is not being encrypted) and that the modem startup speed will be

4800 bit/s when switching over to crypto-voice or crypto-data mode.

I plain voice lsp 2.4 | in the upper line of the display indicates that the user has selected the

'loudspeaking' function and that the modem startup will be 2400 bit/s.

I crypto voice 2.4 | denotes that crypto security has been established, so that only

encrypted speech is passed to the line. '2.4' indicates that the actual bit rate equals 2400 bit/s.

I crypto voice hfr 9.6 I in the upper line of the display indicates that the user has selected the

'handsfree' function and that the actual bit rate is equal to 9600 bit/s.

I crypto data 4.8 I denotes that the apparatus is in the crypto-data mode (4800 bit/s) and
that crypto security is guaranteed.

The lower display line shows the information which plays a supporting part in the operation of
the Secure Telephone Set, e.g. a keyed-in subscriber number, a menu line, etc.

Modem Speed

The modem speed is the bit rate the CELP vocoder (9600 or 4800 bit/s) or LPC-10 vocoder
(2400 bit/s) uses during a crypto voice or crypto data connection.

The PNVX will use the modem startup speed to setup a crypto connection. This modem startup
speed can be the one which has been stored together with the subscriber number in the number

memory or the default one (which has been designated via the menu). The modem startup speed

can be changed by pressing the MODEM button when the handset is replaced or during a plain

voice connection.

If synchronisation is not possible at the modem startup speed (e.g. poor line or PNVX 6317 at
the other end) and if the "Auto fallback mode" is enabled, the PNVX 6318 will automatically

try to synchronise at a lower modem speed.

P h i l i p s C r y p t o B . V . 1 9

SECURE TELEPHONE SET SYSTEM DESCRIPTION

The modem speed can also be changed manually during a crypto connection by pressing the
modem button. The PNVX will then use the new modem speed and re-synchronise.

Keypad layout

DATA enter MENU i t MODEM

CRYPTO 1 2 3

n-x-o

PLAIN 4 5 6 MEM

LSP 7 8 9

MUTE

*

0 # R

Fig. 11: Keypad layout

«-

rr-x-o

DIAL

Philips Crypto B.V. 20

SECURE TELEPHONE SET

GLOSSARY OF TERMS AND ABBREVIATIONS

SYSTEM DESCRIPTION

TERM/ABBREVIATION

A/D

BER

BIT

CCITT

CCITT-V.22bis

CCITT-V.24

CCITT-V.28

CCITT-V.32

DESCRIPTION

Analog-digital

Bit Error Rate

Built-in Test

Comite Consultatif International Telephonique et
Te l e g r a p h i q u e

2400 bit/s duplex modem using the frequency division
standardised for use on the general switched telephone
network and on point-to-point 2-wire leased telephone-type
circuits.

List of definitions for interchange circuits between Data
Terminal equipment (DTE) and Data Circuit-terminating

Equipment (DCE).

Electrical characteristics for unbalanced double-current
interchange circuits.

A family of 2-wire, duplex modems operating at data
signalling rates of up to 9600 bit/s for use on the general

switched telephone network and on leased telephone-type
circuits.

CELP

CLK

CONV.

D/A

DFT

DRT

DSP

EEPROM

EIA

EPROM

GND

HCMOS

HF

Code Excited Linear Prediction

Clock pulse

Converter

Digital-analog

Discrete Fourier Transform

Diagnostic Rhyme Test

Digital Signal Processor

Electrically Erasable Programmable Read-Only Memory

Electronic Industries Association

Erasable Programmable Read-Only Memory

Ground

High-speed CMOS

High Frequency

Philips Crypto B. V.

21

SECURE TELEPHONE SET

SYSTEM DESCRIPTION

TERM/ABBREVIATION

HFR

I/O

IZF

kB

LCD

LPC

LSP

MIC

MON

MTBF

MTTR

oc

PCM

DESCRIPTION

(continued)

HandsFRee

Input/Output

Instituut voor Zintuig Fysiologie (Institute for Sensory
Physiology)

kiloByte

Liquid Crystal Display

Linear Predictive Coding

LoudSPeaking (or LoudSPeaker)

Microphone

Monitor

Mean Time Between Failures

Mean Time To Repair

Opto-coupler

Pulse Code Modulation

PKC

PSTN

RAM

rel

RS232-C

RST

SYNC

TEL

tr

VOCODER

Personal Key Card

Public Switched Telephone Network

Random-Access Memory

Relay

Recommended Standard concerning: Interface between data

terminal equipment and communication equipment employing

serial binary interchange.

Reset

Synchronisation

Te l e p h o n e

Transformer

Voice Coder

Philips Crypto B.V.

22

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