Field of the Invention

This invention relates to a method and apparatus for protecting an input terminal from video surveillance. A particular, but not exclusive, application of the invention is the protection of Automated Teller Machines (ATMs) and Chip and PIN (Personal Identification Number) units against video surveillance by wireless video cameras.

Background to the Invention

An automated teller machine (ATM) (usually called a "Cash Point" in the United Kingdom) dispenses cash on the basis of information it reads from a user's credit card and a Personal Identification Number (PIN) input by the user via the ATM's numeric keypad. Similarly, a Chip and PIN unit effects payment in shops, restaurants and such like on the basis of the information it reads from a user's credit card and the user's PIN. The PIN is again input by the user via a numeric keypad on the Chip and PIN unit. Unfortunately credit cards frequently come into the hands of criminals. This might happen by theft or by production of fake duplicate credit cards based on credit card numbers or personal details obtained by the criminals. However, without knowledge of the PIN associated with a credit card, criminals are limited to using credit cards via the telephone or internet or in shops, restaurants and such like that rely on a user's signature on the back of the card for identification and authentication. Criminals are therefore expending much effort in trying to obtain the PIN number associated with a credit card at the same time as stealing the card or the card number and personal details required to produce a fake duplicate card. One way in which criminals are succeeding in doing this is by snooping on ATMs and Chip and PIN units. This snooping can take a variety of forms. However, it frequently involves the use a wireless video camera mounted on or near to the ATM or Chip and PIN unit for recording an image of the credit card as it is read by the ATM or Chip and PIN unit and recording input of the user's PIN via the numeric keypad. This is turning into a serious problem for banks and money lenders, who are becoming liable for increasingly large amounts of money defrauded in this way. Suitable wireless video cameras are now widely available. They generally comprise a small camera unit having a lens for gathering an image, a charge-coupled device (CCD) for converting the image into a video signal, a radio transmitter for transmitting the video signal and a power supply. A remote recording unit receives the transmitted video signal, which it can display on a monitor or record, e.g. on a video tape. As the number of components of the camera unit are minimised, the camera unit can be very small. In addition, the recording unit can be operated some distance, e.g. a few hundred metres, away from the camera unit. The use of wireless cameras usually therefore goes unnoticed by users and security services alike. The present invention seeks to overcome this problem. Summary of the Invention

According to a first aspect of the present invention, there is provided an apparatus for protecting an input terminal, the apparatus comprising: a receiver for receiving a radio signal; means for determining that the received radio signal is likely to represent a video signal to have been transmitted from the vicinity of the input terminal; and means for preventing use of the terminal upon such determination. According to a second aspect of the present invention, there is provided a method of protecting an input terminal from video surveillance, the method comprising: receiving a radio signal; determining that the received radio signal is likely to represent a video signal and to have been transmitted from the vicinity of the input terminal; and preventing use of the terminal upon such determination. So, the transmission of a signal from a wireless camera in the area immediately surrounding an input terminal, e.g. an ATM or a Chip and PIN unit, is detected. The terminal can then be shut down or an alert issued to prevent use of the terminal. Thus, the possibility of criminals recording images of credit cards and the input of their associated PIN numbers is eliminated. There are various ways in which it can be determined that the received radio signal has been transmitted by a wireless video camera or such like. For example, wireless video cameras typically use certain frequency bands for signal transmission. The determination may therefore comprise determining that the radio signal is received in a predetermined frequency band. The predetermined frequency band may be between around 50 MHz to around 6 GHz. Similarly, video signals have certain inherent characteristics. In particular, video signals typically include synchronisation information specifying the beginning of new image frames and indeed new lines in each frame. This is usually referred to as vertical and horizontal synchronisation information and is repeated at regular intervals in a video signal. So, in another preferred example, the determination comprises determining that the radio signal includes periodic modulation characteristic video synchronisation information. For example, a radio signal modulated using amplitude modulation (an AM radio signal) may periodically have a certain amplitude that represents a vertical synchronisation signal. This periodic signal component can therefore be detected to make the determination. Either or both vertical and/or horizontal synchronisation information may be detected. However, detection of vertical synchronisation information is preferred, as this tends to be the same for most cameras. So, the periodic modulation may be characteristic of the vertical synchronisation component of a video signal. In particular, the periodic modulation might be at around 50 Hz (as it would be for a Phase Alternation Line (PAL) television signal). A radio signal representing a video signal might have been transmitted from the vicinity of the input terminal if it is received by a receiver mounted near the input terminal. It is therefore preferred that the receiver is mounted on or near to the input terminal, or at least has a receiving antenna mounted on or near the input terminal. Likewise, it is preferred that the radio signal is received substantially at the input terminal. Determination that the radio signal is likely to have been transmitted from the vicinity of the terminal might therefore simply comprise successfully receiving the signal. However, at any one time, many radio signals representing video signals may be receivable, but not all of these, or indeed none of these, need necessarily have been transmitted from the vicinity of the input terminal, let alone result from video surveillance of the terminal, e.g. by a wireless video camera. So, in a preferred example, the determination comprises determining whether the signal is received from a range less than a predetermined range. The predetermined range might be around 1.5 m. In other words, the determination comprises determining that the signal has been transmitted within a predetermined range of the input terminal. This might be achieved in a variety of ways. In particular, it is preferred that the determination comprises determining whether the signal is received at greater than a predetermined signal strength. Signal strength can be representative of the range from which a radio signal has been transmitted. The predetermined signal strength might be the strength with which a signal is received from a typical wireless camera around 1.5 m away. As mentioned above, once it has been established that the received radio signal is likely to represent a video signal transmitted from the vicinity of the input terminal, use of the terminal is prevented. For example, the use prevention means may comprise means for alerting a user that the input terminal may be under video surveillance (e.g. by displaying an appropriate message on a display screen). Similarly, the use prevention means may comprise means for alerting a remote central control station that the input terminal may be under video surveillance. This might enable security staff monitoring the input terminal from the control station to alert the police and/or control disabling of the input terminal. In another example, the use prevention means may comprise means for disabling the input terminal. The disabling means might block use of the terminal. However, it is preferred that the disabling means comprises means for interrupting power supply to the terminal. This might be for a predetermined period. Interruption or switching off of the power supply is particularly straightforward to implement. Indeed, the disabling means could even comprise a circuit breaker between the input terminal and a power supply. So, particularly in the case of an ATM, the whole apparatus of the invention could be housed in a circuit breaking device, e.g. for insertion between a power cable of the input terminal and a power supply used by the input terminal. This makes retrospective fitting of the apparatus to input terminals cheap and straightforward. Of course, the invention is not limited to this and the apparatus can alternatively be mounted on or incorporated in the input terminal as desired. Preferred embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings. Brief Description of the Drawings

Figure 1 is a schematic illustration of a Automated Teller Machine (ATM); and Figure 2 is a schematic illustration of an anti-surveillance device according to the invention for use in the ATM of figure 1.

Detailed Description of the Preferred Embodiments

Referring to figure 1 , an Automated Teller Machine (ATM) 1 has a card reader 2 into which a credit card (not shown) can be inserted by a user. In this embodiment, the card reader 2 is a magnetic strip reader able to read information carried in the magnetic strip of a conventional credit card. In other embodiments, it is possible for the card reader 2 to be a chip or smart card reader able to read information carried in a microchip embedded in the credit card. The ATM 1 also has a keypad 3 via which a user can enter the Personal Identification Number (PIN) associated with the card and interact with the ATM 1 , e.g. by answering questions with a yes key or a no key and entering an amount of cash requested to be dispensed by the ATM 1. A display 4 is provided on the ATM 1 for outputting information to a user. In this embodiment, the display 4 is a computer monitor. Of course, cash can also be dispensed by the ATM 1 through a dispensing slot 5 in the conventional manner. The ATM 1 is connected to a central controller 6 via a communications system 7. The central controller 6 interfaces with a bank clearing system to obtain authorisation for the dispensing of cash by the ATM I and information such as account balances. The central controller 6 also monitors operation of the ATM 1 , for example by poling it periodically to check that it remains connected to the communication system 6. Power is supplied to the ATM 1 from a power supply 8, which, in this embodiment, is the local electricity mains supply. Mounted inside the ATM 1 is an anti-surveillance device 9, not shown in figure 1 , but illustrated schematically in figure 2. The device 9 has an antenna 10 adapted to pick up radio signals over wide frequency range, e.g. at least 50 MHz to 6 GHz. The antenna 10 is connected to a radio receiver I 1 that is able to filter and amplify the output of the antenna 10. The receiver 11 is, in turn, able to output the filtered and amplified signal to a signal processor 12. The signal processor 12 is adapted to analyse the filtered and amplified signal to determine whether it is likely to represent video data transmitted from the vicinity of the ATM 1 , as described in more detail below. The signal processor 12 is connected to an output unit 13 so that, in the event of such determination by the signal processor 12, the signal processor 12 can output a positive determination signal to the output unit 13. The output unit 13 is adapted to prevent use of the ATM 1 when it receives a positive determination signal from the signal processor 12. More specifically, in this embodiment, the output unit 13 is able to output a signal A, which is a command to switch off power to the ATM 1 from the power supply 8. In other embodiments, the signal A is an alert transmitted to the central controller 6 via the communication network 7; or a command that causes the ATM 1 to stop dispensing cash and to display a warning on its display 4. In use, whenever the ATM 1 is operational, the anti-surveillance device 9 is also operational. In other words, whilst the ATM 1 is turned on, the anti-surveillance device 9 continually monitors the radio signals it receives via its antenna 10. More specifically, the signal processor 12 monitors filtered and amplified signal it receives from the receiver 11. In one embodiment, the signal processor simply compares the strength of the signal it receives from the receiver to a predetermined threshold level. If the signal strength is above the threshold level, the signal processor 12 outputs a positive determination signal to the output unit 13, which, in turn, outputs signal A as described above. In another embodiment, the signal processor correlates the signal it receives from the receiver 11 with a 50 Hz reference signal. If the signal processor 12 identifies that the signal it receives from the receiver 11 contains a significant component at 50 Hz, it outputs the positive determination signal to the output unit 13, which, in turn, outputs signal A as described above. The described embodiments of the invention are only examples of how the invention may be implemented. Modifications, variations and changes to the described embodiments will occur to those having appropriate skills and knowledge. These modifications, variations and changes may be made without departure from the spirit and scope of the invention defined in the claims and its equivalents.