AU766464B2 - A security apparatus for a telephone line and a method for securing a telephone line - Google Patents

Description

WO 99/05842 PCT/AU98/00595 -1-

TITLE

"A Security Apparatus For A Telephone Line And A Method For Securing A Telephone Line" FIELD OF THE INVENTION The present invention relates to a security apparatus for a telephone line and a method for securing a telephone line.

BACKGROUND ART Recent reports of children incurring significant telephone charges using their parents' telephone has highlighted the need for increased telephone line security.

Some telecommunications carriers offer an electronic lock for telephones whereby a first PIN is entered to disable the telephone and a second PIN is entered to enable the telephone. Whilst this electronic lock provides some protection, it is inflexible in that the telephone is either disabled or fully enabled, whereas most parents want to provide their children with limited access to the telephone. Further, when the telephone is enabled there is no restriction on the type of call, such as international, long-distance or local calls, that can be placed using the telephone.

Australian patent specification AU-A 44438/96 describes a multi-user telephone arrangement which provides for multiple users to use a single telephone. The specification describes the telephone exchange including an exchange processor which is used to identify each user via a user ID and PIN and to bill each telephone call to the corresponding user ID. Whilst this system is useful in situations such as university student houses, it requires the presence of special equipment at the telephone exchange and for each user to have an account with the telecommunications carrier.

WO 99/05842 PCT/AU98/00595 -2- Australian patent specification AU-B 38513/93 describes a telephone sub-set including a processor and a memory in which a credit limit is entered by the proprietor into the memory. The telephone may then be used until such time as the credit is used. The telephone sub-set described in specification AU-B 38513/93 does not provide for any form of restriction to be placed on the type of call.

SUMMARY OF THE INVENTION In accordance with one aspect of this invention, there is provided a security apparatus for a telephone line, comprising: switching means for connection in-line with said telephone line between a telephone exchange and at least one telephone, facsimile machine or the like; processor means and associated memory, said memory storing for each of a plurality of users a security code and access privileges for each of a plurality of outgoing call types; said processor means including decoder means responsive to dial signals on the telephone line from the at least one telephone, said processor means determining therefrom the call type of an outgoing call; said processor means arranged to control the switching means to reset the telephone line if an incorrect security code is entered or if a user has insufficient access privilege for the call type of the outgoing call.

Preferably, said memory also stores at least one priority number, said processor means being arranged to allow outgoing calls to any of said priority numbers irrespective of said access privileges.

WO 99/05842 PCT/AU98/00595 -3- Preferably, the processor means is arranged to allow outgoing calls to any of said priority numbers without requiring a security code to be entered.

Preferably, said processor means determines the call type by analysing the dialled number.

Preferably, said call types include at least two from the following list: local, long distance, international, mobile, premium.

Preferably, the switching means is arranged such that in the event of a power failure to said security apparatus, said switching means is closed to permit outgoing and incoming calls.

Preferably, said access privileges for each call type include at least one of: maximum number of calls per predetermined time interval; maximum length of each call; and time of day calls may be made.

Preferably, said processor is arranged to provide a warning indication prior to the maximum length of call being reached.

Preferably, said memory also stores at least one barred number, said processor means being arranged to prevent outgoing calls to any of said barred numbers irrespective of said access privileges.

Preferably, the processing means is responsive to said telephone line to receive security codes therefrom via a telephone or other device connected to said telephone line.

Preferably, the processor means controls the switching means to disconnect the telephone line when receiving a security code from said telephone, facsimile or the like.

WO 99/05842 PCT/AU98/00595 -4- Preferably, the security apparatus further comprises a power supply to which the telephone, facsimile or the like are connected when the switching means disconnects the telephone line.

Preferably, said access privileges can be edited by a master user upon entry of a master security code.

Preferably, one of said priority numbers is fixed.

Preferably, the security apparatus includes a key pad in communication with the processor means on which the security codes may be entered.

Preferably, the security apparatus is provided integral with a telephone or facsimile machine, said key pad being the telephone or facsimile machine's key pad.

In accordance with a further aspect of this invention, there is provided a method for securing a telephone line, comprising the steps of: providing switching means in-line with said telephone line between a telephone exchange and at least one telephone, facsimile machine or the like; allocating for each of a plurality of users a security code and access privileges for each of at least two call types; upon attempted use of said telephone line: determining the call type of an outgoing call; and using said switching means to reset said telephone line if an incorrect security code is entered or if a user has insufficient access privilege for the call type of the outgoing call.

WO 99/05842 PCT/AU98/00595 BRIEF DESCRIPTION OF THE DRAWINGS This invention will now be described with reference to one embodiment thereof and the accompanying drawings, in which: Figure 1 is a block diagram of the security apparatus according to the preferred embodiment of the invention; Figure 2 is a block diagram of the processor and associated hardware of the security apparatus shown in figure 1; Figure 3 shows the housing of the security apparatus in figure 1; Figure 4 is a flowchart of the main routine controlling operation of the processor; Figure 5 is a flowchart of the parameter definition routine; Figure 6 is a flowchart of the print routine; Figure 7 is a flowchart of the look routine; and Figure 8 is a flowchart of the incoming call routine.

DESCRIPTION OF THE PREFERRED EMBODIMENT The embodiment is directed toward a security apparatus which is provided as a unit separate from a telephone handset, facsimile machine or the like. It should be appreciated however that the invention is equally applicable to security apparatus which are incorporated into a telephone handset or facsimile machine.

The embodiment provides for a security apparatus 10 for a telephone line 12 extending between a telephone exchange 14 and a telephone handset 16. The security apparatus 10 comprises a relay 18 provided in the telephone line 12 intermediate the telephone exchange 14 and the telephone handset 16, an LCD WO 99/05842 PCT/AU98/00595 -6- (liquid crystal display), a battery backup and telephone line power supply 21, a meter pulse detector circuit 22, a real time clock 23, a DTMF (dual tone multiple frequency) and CND (calling number display) decoder circuit 24, a key pad 26, a voice playback circuit 27, a flash memory 28 and a program memory 29, each of which is interfaced to a processor 30. The processor 30 used in the embodiment is the MC68HC11K1 micro-controller manufactured by Motorola, although it should be appreciated that other processors may be utilised.

The processor 30 controls operation of the relay 18 via a relay interface circuit 19.

The relay 18 is arranged such that the telephone line 12 is connected to the normally-closed contacts of the relay 18. Consequently, in the event of a power failure to the security apparatus 10 the telephone handset 16 is still operable.

The telephone line power supply 21 is connected to the normally-open contacts of the relay 18.

The meter pulse detector circuit 22 is connected to the telephone line 12 and is arranged to indicate to the processor 30 when a telephone call placed using the telephone handset 16 is picked up by the recipient. This information is used by the processor 30 to log to the length of the telephone call and to monitor the length of the telephone call.

There are three ways commonly used to indicate that the handset was picked up by the recipient, namely line polarity reversal, a 50Hz longitudinal signal or a 12kHz transverse signal. The meter pulse detection circuit 22 includes a circuit to detect each of these forms of indication. Which of these circuits is connected to the processor 30 is controlled via a jumper switch (not shown). It should be appreciated that if it is known the telephone line 12 utilises only one form of indication, the meter pulse detection circuit 22 may comprise only one of the three circuits. Additionally, other circuits may be provided if alternative methods are used by the carrier provider.

WO 99/05842 PCT/AU98/00595 -7- The real time clock 23 provides date and time information to the micro-processor which is used to record the date and time that telephone calls are made. In the embodiment, the real time clock 23 used is a 68HC68T1 CMOS serial real time clock manufactured by Motorola.

The DTMF and CND decoder circuit 24 is connected to the telephone line 12 and provides the processor 30 with information corresponding to DTMF or CND signals appearing on the telephone line 12. In the embodiment, the dual tone multiple frequency receiver integrated circuit MC145436 manufactured by Motorola was utilised to provide DTMF signal decoding, such as those produced by a tone dial telephone handset. Decoded DTMF information received from the DTMF and CND decoder circuit 24 is used by the processor 30 to allow security codes to be entered from the telephone handset 16 and to monitor telephone numbers dialled from the telephone handset 16. The DTMF and CND decoder circuit 24 also utilises a CML FX602 calling number display integrated circuit which communicates the telephone number of incoming calls to the microprocessor 30 for display on the LCD The key pad 26 includes numeric keys 32 and function keys 34. The key pad 26 is used to control operation of the security apparatus 10 and can also be used to enter security codes.

The security apparatus 10 further comprises a communications port 36, a serial printer 38, a battery level indicator 39, a tamper switch 40, a telephone line status circuit 42 and a touch key input 44, each of which is interfaced to the processor The serial printer 38 is connected to the processor 30 via the communications port 36 which provides an RS-232 interface. Alternatively, the security apparatus can be connected to a computer using the communications port 36.

WO 99/05842 PCT/AU98/00595 -8- The battery level indicator 39 comprises a voltage divider circuit which provides an indication of the current battery voltage to the micro-processor 30. The output of the battery level indicator 39 is input to an analogue-to-digital input of the processor 30. When the output from the battery level indicator 39 indicates that the battery in the power supply and battery back-up 21 is sufficiently low, the processor 30 flashes a warning message on the LCD 20 that the battery level is low.

The telephone line status circuit 42 is arranged to provide information to the processor 30 regarding whether the telephone handset 16 is on-hook or off-hook, and also to provide an alarm indication if the security apparatus 10 is disconnected from the telephone line 12.

The touch key input 44 consists of a touch probe mounted on the exterior of the security apparatus 10. The touch probe is designed to read touch buttons, which are similar to the DS2401 serial number integrated circuit by Dallas semiconductor. Touch buttons are typically provided in a can package, which is similar in appearance to a button battery. The touch key input 44 is provided for high security applications, where in addition to a security code the user will also be required to press a touch button to the touch key input in order to gain access to the telephone line.

The security apparatus 10 further comprises gate arrayed logic 47a and a selector circuit 47b to provide the necessary logic for addressing the flash memory 28, the EPROM memory 29 and the LCD The security apparatus 10 further includes a master key switch 48 which is connected to interrupt pin IRQ of the processor 30. The master key switch 48 is used to activate the parameter definition routine, to be described hereinafter.

The security apparatus 10 is provided in a housing 50. The tamper switch 40 is arranged such that opening the housing 50 will open the switch 40 and thereby WO 99/05842 PCT/AU98/00595 -9provide indication to the processor 30 that the security apparatus 10 has been tampered with.

The processor 30 operates under control of computer software stored in the memory 29. The flash memory 28 also includes, for each user, a security code and access privileges including the maximum number of each call type for local, long distance and premium calls, the maximum length of each type of call and the times of day each type of call can be made.

In the embodiment, the local call type is reserved for calls which are within the same area as the security apparatus, and accordingly incur a relatively small tariff from the telecommunications provider. The long distance call type is defined as being calls to promote areas within the same country and calls to mobile telephones, which incur a time-based higher charge compared with local calls.

The premium call type is reserved for international telephone calls and calls to high-tariff pay by the minute services. It should be appreciated that the number of call types and their definition may be varied in other embodiments.

An example of security codes and access privileges for three users is set out below in table 1.

User 1 User 2 User 3 security code 8372 9464 8112 max local calls unlimited 60 max long-distance unlimited 10 calls max premium calls unlimited 3 1 max local call length unlimited 60 mins 60 mins max long distance unlimited 15 mins 15 mins call length WO 99/05842 PCT/AU98/00595 max premium call unlimited 15 mins 15 mins length local access times 0:00-23:59 8:00-22:00 15:00-20:00 long distance access 0:00-23:59 15:00-20:00 15:00-19:00 times premium access 0:00-23:59 0:00-23:59 0:00-23:59 times Table 1 In. table 1 above, user 1 has unlimited access privileges, whilst user 2 and user 3 have restrictions on their access privileges. User 2 is limited to 60 local calls, long distance calls, and three premium calls per pre-determined time period. The pre-determined time period is definable by the master user and may be one week or one month, for example.

In addition, user 2 and user 3 have call length limitations on each type of telephone call. Finally, user 2 and user 3 have restrictions regarding during what time of the day local and long distance telephone calls may be made.

The flash memory 28 also includes up to three priority numbers and up to three barred numbers. Examples of priority numbers and barred numbers are set out in table 2 below.

Priority numbers 000 222 1111 Barred numbers 1902 293 693 005511523 0055 12395 Table 2 WO 99/05842 PCT/AU98/00595 -11- Calls to priority numbers may be made at any time irrespective of access privileges. Further, it is not necessary to enter a security code in order to call a priority number. Calls to barred numbers may not be made, irrespective of access privileges. The implementation of barred and priority numbers will be described below.

Figure 4 shows the main program routine executed by the processor 30. At program initialisation is performed. At 52, the LCD 20 is updated with the current date and time from the real time clock 23.

At 54, whether a call has been initiated is determined according to information received from the DTMF decoder circuit 24. If a call has not been initiated, program control returns to 52. If a call has been initiated, the dialled number is compared with the priority numbers at 56. If the dialled number matches any one of the priority numbers, the call is permitted and the end of the call is awaited at 58. When the call has ended program control returns to 52.

If the dialled number is not a priority number the relay 18 is switched to the normally-open position at 59. This is done so that the security code is not interpreted by the telephone exchange 14 as being part of the telephone number.

Since modern telephones rely on power from the telephone line 12 for their power source, the normally-open contacts of the relay 18 are connected to a telephone line power supply 21, such that the telephone 16 can continue operation.

The dialled number is checked at 60 to determine if the dialled number commenced with which is used to indicate that a security code follows. If the dialled number does not commence with the telephone line is reset at 62 by opening and closing the relay 18, thereby terminating any call. Program control then returns to 52.

Any further dialled numbers are then compared with the security codes. If the dialled number does not correspond with a security code, a pre-recorded voice WO 99/05842 PCT/AU98/00595 -12message is played to the user via the voice IC 27. The voice IC 27 plays the message onto the telephone line 12 connected to the telephone. Three attempts are allowed at entering a security code. If a valid security code is not entered in the three attempts, the telephone line is re-set at 62 and program control then returns to 52. To prevent continual attempts to guess a security code, if three incorrect security codes are entered consecutively, the security apparatus 10 will not allow further attempts at entering security codes for a period of one minute.

During this time, calls to priority numbers may still be made.

If the comparison indicates that the dialled number matches a security code, the relay 18 is switched to the normally-closed position at 64 so that the call can proceed.

Once the relay 18 is returned to the normally-closed position at 64, the commencement of dialling the number is awaited at 66. At 67, a check is performed to determine whether the call has dropped-out because of delays in dialling the number. If the call has dropped out, the telephone line is reset at 62 and control returns to 52, otherwise the call is again awaited at 66.

Once the number has commenced being dialled, at 68 the dialled number is categorised into one of the call types, namely local, long distance or premium.

The categorisation can be performed in a number of ways, such as by comparison of the length of the dialled number and by comparison of the first several digits of the telephone number. For example, in Australia, if the number begins with 0055, 0011 or 0015, the call type is premium, and if the number begins with 08, 02, 03, etc the call type is long distance. The dialled number is displayed on the LCD Once the call type has been determined, a check of whether the user has reached their maximum number of calls is made at 70. If the user has already made their maximum number of calls of this call type, the telephone line is reset at 62, thereby disconnecting the call. Program control then returns to 52.

WO 99/05842 PCT/AU98/00595 -13- If the user has not reached their maximum number of calls, a check is then made at 71 as to whether the user is permitted to make the call type at the time of day.

If the call is being made outside of the allowable times, the telephone line is reset at 62 thereby disconnecting the call and program control is then returned to 52.

If the user is making the call within an allowed time period, the dialled number is compared with the barred numbers. If the dialled number matches with any one of the barred numbers, the telephone line is reset at 62, thereby disconnecting the call and program control is returned to 52.

If the user is making the call to a non-barred number, upon detection of a meter pulse by the meter pulse detector circuit 22, the commencement of the call is logged.

At 73 a check is made of whether the length of the call has exceeded the length of call permitted for the user for the call type or the user has terminated the call.

If the maximum length of call has not been reached and the call has not been terminated by the user, the elapsed call time is displayed at 74. A comparison is then made at 75 as to whether the elapsed length of call is less than 45 seconds from the maximum allowable call length for this type of call. If the call length is not within 45 seconds, program control returns to 73, otherwise a warning message is displayed on the LCD 20 and played to the user via the voice playback circuit 27 at 76 to provide an indication to the user of impending disconnection of the call. Program control then also returns to 73.

If the maximum length of call has been reached, or if the call has been terminated by the user, the logged call data for that call is completed and stored at 77. The user's number of calls is updated to reflect the call.

At 78, a check is performed as to whether the user indicated they wish to make a follow-on call. In the embodiment, the user can provide such an indication by pressing the key during a call. If the user indicated they wish to make a WO 99/05842 PCT/AU98/00595 -14follow-on call, the telephone line is reset at 78a and program control returns to 64.

The user can then dial a further call without having to re-enter their security code.

If the user did not provide an indication that they wish to make a follow-on call, the telephone call is reset at 62 and program control returns to 52.

The user security codes, user access privileges, priority numbers and barred numbers are programmable by use of a master key. The master key is a physical key which is required to activate the master key switch 48. When activated and the master-security code is entered, the processor 30 executes the parameter definition routine shown in figure 5. The parameter definition routine consists of four sub-routines, an accounts sub-routine 80, a clock sub-routine 82, a priority number sub-routine 84 and a barred number sub-routine 86. The parameter definition routine also includes an exit function 88. While the parameter definition routine is executing, the security apparatus 10 does not perform any line control on the telephone line 12. This allows the telecommunications carrier to perform diagnostic checks without interference from the apparatus The accounts sub-routine 80 requests a user number at 90 and a security code for that user at 92. The maximum number of calls for that user for local, long distance and premium call types are requested at 94, 96 and 98 respectively.

The maximum length of local calls, long distance calls and premium calls are then requested for that user at 100, 102 and 104, respectively. Finally the allowable times during which local calls, long distance and premium calls can be made are requested at 106, 108 and 110 respectively. The user is then queried at 112 whether they wish to proceed to the clock sub-routine 82 or to the exit function 88.

The clock sub-routine 82 is used to set the date and time of the real time clock 23. At 114 the day number and month number are entered. The year number is entered at 116. The time in hours and minutes is entered at 118 and finally the day of the week from 1-7 is entered at 120. At 122 the user is prompted whether to proceed to the priority numbers sub-routine 84 or to the exit function 88.

WO 99/05842 PCT/AU98/00595 The priority numbers sub-routine 84 prompts the user to enter up to three priority numbers at 124, 126 and 128, respectively. At 130 the user is prompted whether to proceed to the barred number sub-routine 86 or to the exit function 88.

It is to be noted that in other embodiments, the first priority number is not programmable. The first priority number will be defined in such embodiments to be the emergency number for the particular country where the unit is sold, for example 000 for Australia and 911 for the USA.

The barred number sub-routine 86 prompts the user to enter up to three barred numbers at 132, 134 and 136 respectively. In the embodiment, if the key is pressed as one of the digits of the barred number, it is treated as any digit. That is, the is treated as a wildcard.

Information is entered in response to the prompts by using the numeric keys 32 and the function keys 34. In this regard, the function keys 34 include a "next" key, a "back" key and a "back space" key.

The function keys 34 also include a "print" key which causes the processor 30 to execute the print routine shown in figure 6. The print routine consists of initialisation at 138 whereupon the user is requested to enter the security code of the master user at 140, in order to prevent unauthorised access to the print routine. The user can then select between whether the data is to be formatted for printing or whether it is to be sent to a computer connected to the communications port 36.

If the user selects that the data is to be formatted for transmission to a computer at 142, the logged data for each user is sent to the communications port 36 at 144, following which the print routine is exited at 146 and program control returns to 52.

Alternatively, if the user selected the data is to be formatted for transmission to a printer connected to the communications port 36 at 148, the user is prompted to WO 99/05842 PCT/AU98/00595 -16enter a user number at 150 for which the data is to be printed, and the date range between which data is to be printed at 152. The data is then transmitted to the communications port 36 at 154, following which the print routine exists at 146 and program control returns to 52.

The function keys 34 also include a "look" key by means of which a user is able to view their account details. Pressing the "look" function key 34 causes the processor 30 to execute the look routine 156 in shown in figure 7. The look routine commences with a prompt to enter a security code at 157 or view a log of calling number display (CND) messages at 158.

If the user chooses to enter a security code, the security code is checked at 159.

If an incorrect security code is entered, the look routine 156 terminates at 160 and control is returned to 52.

If a valid security code is entered, the user can view the remaining number of calls they may make for each of local, long distance and premium call types at 161, 162 and 163, respectively; the maximum length of call for local calls, long distance calls and premium calls at 164, 165 and 166, respectively; and the times during which they made local calls, long distance calls and premium calls at 167, 168 and 169, respectively. Navigation between the information displayed at 161 169 is achieved using the "next" key and "back" key.

If the user elects to view the CND message log, their most recent CND message is displayed at 158. The user is then prompted at 170 whether they wish to delete or retain this message. If the user elects to retain the message, the next message is retrieved at 172. If the attempt to retrieve the next message indicates that the previous message was the final message, premium control forwards to 160. Otherwise, the next message is displayed at 158, and the user again prompted whether they wish to delete the message at 170.

WO 99/05842 PCT/AU98/00595 -17- If the .use wishes to delete the message, the message is erased at 174, whereupon a comparison is made as to whether the deleted message was the last CND message. If not, program control is forwarded to 172 to obtain the next message, otherwise the look routine terminates at 160.

If a call is started, either incoming or outgoing, whilst the look routine is operating, the look routine is aborted. Further, whilst a call is in progress, the look routine is disabled.

When an incoming call is detected by the CND circuit 24, the processor executes the calling number display routine 180 shown in figure 8. If available, the calling number is displayed on the LCD 20 at 182. The elapsed time of the incoming call is also displayed on the LCD 20 at 184. At 186, a check is made as to whether the incoming call has terminated. If the call has not terminated, the program returns to 184 and updates the duration of the call. Otherwise, the calling number display routine 180 terminates at 188 and program control returns to 52.

The security apparatus 10 further includes status LEDs 190,192 and 194. The status LED 190 is used to indicate mains power to the security apparatus The status LED 192 is used to indicate that the security apparatus 10 is operating on battery power. The status LED 194 is used to indicate if the security apparatus 10 has been disconnected from the telephone line 12.

The security apparatus 10 also monitors the telephone line 12 for calls that are made which by-pass the security apparatus 10. If information received from the DTMF decoder circuit 24 indicates that a telephone call is being made and the security apparatus 10 attempts to terminate the call by resetting the telephone line because of insufficient authorisation or an incorrect security code and the meter pulse detector circuit 22 continues to receive metered pulses, the security apparatus 10 logs the call as a call made by the user "by-pass". These calls will appear on the log printed using the print routine shown in figure 6. Call by- WO 99/05842 PCT/AU98/00595 -18passing would occur if a telephone was connected between the telephone exchange 14 and the relay 18.

When resetting the telephone line 12, the relay 18 is caused to open for two seconds, which is sufficient for the exchange 14 to terminate the call.

Although not shown in figure 4 for simplicity, if three incorrect security codes are entered consecutively, the security apparatus 10 will terminate all outgoing calls for one minute, unless the calls are to one of the priority numbers.

The function keys 34 also include a "change PIN" function key by means of which a user is able to change their security code. In the embodiment, the apparatus assigns the user a new security code randomly from the unused security codes.

The new security code is spoken to the user via the voice IC.

The master key switch 48 has four settings, "run", "program", "reset" and "override". The "run" setting is the normal operating state of the security apparatus 10. The "program" setting is used to access the parameter definition routine. The "reset" setting is used to momentarily reset the security apparatus in the event of a program halt. The "override" position provides a manual override to the security apparatus 10, whereby the relay 18 will be switched to always closed in respective of the operation of the processor If the tamper switch 40 indicates that access to the inside of the housing 50 has been attempted, a message that the unit has been tampered with will appear in the LCD 20. The message will remain on the LCD 20 until the unit is reset using the master key.

It should be appreciated that the invention is not limited to the particular embodiment above.

WO 99/05842 PCT/AU98/00595 -19- For example, the number of users the security apparatus can control, the number of call types and the call types may be varied. Also, the invention can equally be applied to several telephone lines.

Further, additional security measures such as a touch-button may be incorporated into the apparatus.

Also, a telephone number index can be incorporated into the apparatus.

Claims (18)

1. A security apparatus for a telephone line, comprising: switching means for connection in-line with said telephone line between a telephone exchange and at least one telephone, facsimile machine or the like; processor means and associated memory, said memory storing for each of a plurality of users a security code and access privileges for each of a plurality of outgoing call types, said access privileges including maximum number of calls per predetermined time interval; said processor means including decoder means responsive to dial signals on the telephone line from the at least one telephone, said processor means determining therefrom the call type of an outgoing call; said processor means arranged to control the switching means to reset the telephone line if an incorrect security code is entered or if a user has insufficient access privilege for the call type of the outgoing call.

2. A security apparatus as claimed in claim 1, wherein the access privileges further include maximum length of each call and time of day calls may be made.

3. A security apparatus as claimed in claim 1 or 2, wherein said memory also stores at least one priority number, said processor means being arranged to allow outgoing calls to any of said priority numbers irrespective of said access privileges.

4. A security apparatus as claimed in claim 3, wherein the processor means is arranged to allow outgoing calls to any of said priority numbers without requiring a security code to be entered.

AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00595 Received 36 July 1999 -21- A security apparatus as claimed in any one of the preceding claims, wherein said processor means determines the call type by analysing the dialled number.

6. A security apparatus as claimed in claim 5, wherein said call types include at least two from the following list: local, long distance, international, mobile, premium.

7. A security apparatus as claimed in any one of the preceding claims, wherein the switching means is arranged such that in the event of a failure in said security apparatus, said switching means is closed to permit outgoing and incoming calls.

8. A security apparatus as claimed in any one of the preceding claims, wherein said predetermined time interval is one week.

9. A security apparatus as claimed in any one of the preceding claims, wherein said processor is arranged to provide a warning indication prior to the maximum length of call being reached.

A security apparatus as claimed in any one of the preceding claims, wherein said memory also stores at least one barred number, said processor means being arranged to prevent outgoing calls to any of said barred numbers irrespective of said access privileges.

11. A security apparatus as claimed in any one of the preceding claims, wherein the processing means is responsive to said telephone line to receive security codes therefrom via a telephone or other device connected to said telephone line.

12. A security apparatus as claimed in claim 11, wherein the processor means controls the switching means to disconnect the telephone line when receiving a security code from said telephone, facsimile or the like. AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00595 Received 30 July 1999 -22-

13. A security apparatus as claimed in claim 12, further comprising a power supply to which the telephone, facsimile or the like are connected when the switching means disconnects the telephone line.

14. A security apparatus as claimed in any one of the preceding claims, wherein said access privileges can be edited by a master user upon entry of a master security code.

A security apparatus as claimed in any one of claims 4 to 14 as dependent upon claim 3, wherein one of said priority numbers is fixed.

16. A security apparatus as claimed in any one of the preceding claims, wherein the security apparatus includes a key pad in communication with the processor means on which the security codes may be entered.

17. A security apparatus as claimed in claim 16, wherein the security apparatus is provided integral with a telephone or facsimile machine, said key pad being the telephone or facsimile machine's key pad.

18. A method for securing a telephone line, comprising the steps of: providing switching means in-line with said telephone line between a telephone exchange and at least one telephone, facsimile machine or the like; allocating for each of a plurality of users a security code and access privileges for each of at least two call types, said access privileges including maximum number of calls per predetermined time interval; maximum length of each call; and time of day calls may be made; upon attempted use of said telephone line: determining the call type of an outgoing call; and AMENDED SHEET (Article 34) (IPEA/AU) PCT/AU98/00595 Received 3o July 1999 -23- using said switching means to reset said telephone line if an incorrect security code is entered or if a user has insufficient access privilege for the call type of the outgoing call. AMENDED SHEET (Article 34) (IPEA/AU)