Tamper detection system and method

A tamper detection system and method which uses a reader and one or more tags to detect tampering near a card reader slot or any other device subject to tampering. An example tamper detection method includes transmitting a signal to a tag adjacent a device susceptible to tampering, and setting an alarm condition when no reply signal or an incorrect reply signal is received in response to the signal.

BACKGROUND

This present invention relates to magnetic stripe readers (MSRs) and more specifically to a tamper detection system and method.

Unauthorized reading of card data, such as data encoded on a magnetic stripe card, while the card is being used (hereafter “card skimming”), is a known type of fraud. Card skimming is typically perpetrated by adding a magnetic read head to a fascia of an automated teller machine (ATM), fuel pump, or other terminal, to read a magnetic stripe on a customer's card as the customer inserts or (more commonly) retrieves the card from a card reader. The fraudster can then create a new card using the card data read by the alien reader.

If the card is a credit card, the fraudster can begin charging purchases to the customer's credit card account. In the case of debit cards, the fraudster must have the customer's personal identification number (PIN). Several techniques may be used by fraudsters to obtain personal identification numbers (PINs) in order to gain access to customer accounts. Fraudsters can use cameras to capture images of a PIN-entry keypad during customer use. Fraudsters can employ a false overlay to the PIN-entry keypad to record entry of the PIN as it is typed. Finally, fraudsters may watch customers (“shoulder surfing”) as the customers enter their PINs. A fraudster can then use the new card and the PIN to withdraw funds from the customer's bank account.

Some installations use preventive measures, such as capacitive sensing devices to detect skimmers. However, capacitive sensing devices are affected by the presence of rain drops and the human hand.

Therefore, a more robust and reliable technique is needed to detect the presence of non-native hardware in the vicinity of a card reader or other device subject to tampering.

SUMMARY

In accordance with the teachings of the present invention, a tamper detection system and method is provided.

An example tamper detection method includes transmitting a signal to a tag adjacent a device susceptible to tampering, and setting an alarm condition when no reply signal or an incorrect reply signal is received in response to the signal.

When a reply signal is received, the example tamper detection method determines frequency response data from the reply signal, compares the frequency response data to reference frequency response data, and sets the alarm condition when the frequency response data does not match the reference frequency response data.

An example tamper detection system includes a tag adjacent to a device susceptible to tampering, and a reader for transmitting a signal to the tag and for setting an alarm condition when the reader fail to receive a reply signal from the tag or fails to receive a correct reply signal from the tag. When the reader receives the reply signal, the reader determines frequency response data from the reply signal, compares the frequency response data to reference frequency response data, and sets the alarm condition when the frequency response data does not match the reference frequency response data.

DETAILED DESCRIPTION

Turning now toFIG. 1, an example tamper detection system10uses reader20and tag30to detect tampering near any device subject to tampering. An example use of system10is to detect tampering of enclosures for secure devices, like payment card readers.

Tag30includes wireless communication circuitry34and antenna34. Wireless communication circuitry34stores a unique tag identifier. In one example embodiment, the tag identifier is an identification bit pattern.

Tag30is powered by a signal from reader20and responds when interrogated by sending a modulated reply signal. In one example embodiment, tag30receives a continuous wave signal from reader20and reflects the continuous wave signal back to reader20using a technique known as backscattering. Wireless communication circuitry34uses the unique tag identifier to modulate the incoming continuous wave signal and produce the modulated reply signal. Thus, tag30produces a unique reply signal containing its own tag identifier. For added security, the tag identifier stored by tag30may be encrypted for later decryption by reader20or computer40.

Tag30may be passive, relying on the energy of the continuous wave signal from reader20for powering wireless communication circuitry34. Alternatively, tag30may be active, relying on a local power source, such as a battery, or power from computer40.

Tag30may be installed at various locations and ways in the vicinity of the card reader slot. In one example embodiment, tag30is affixed to a card reader guide cover which acts as a fraudulent device inhibitor (FDI). Antenna32may be affixed or embedded into the card reader guide cover. Since card reader guide covers are typically made of plastic, antenna32may be integrated into the plastic of the card reader guide cover with a technique similar to IMD (In Mold Decoration) or may be printed directly on the plastic with conductive ink. The number and locations of tags30and the sensitivity of reader20determine the coverage area.

In another example embodiment, tags30may be positioned in a fascia of an ATM, fuel pump, kiosk, or other terminal to detect attempts to install a camera or a keypad overlay to capture pin entry.

Antenna34may include a segmented square loop antenna, which results in a high sensitivity to a skimmer brought closer than one and half wavelength. Other antenna types are also envisioned.

Reader20sends out interrogation signals and receives reply signals from tag30. For this purpose, reader20includes wireless communication circuitry24and antenna26.

Wireless communication circuitry24transmits short-range, low power continuous wave signals. Wireless communication circuitry24demodulates reply signals from tag30and may additionally determine frequency response data, including amplitude and/or phase differences between reader and tag signals.

In one example embodiment, wireless communication circuitry24produces continuous wave signals in the microwave band. At a target frequency of 5.8 GHz or higher and a quarter wavelength in size results in antenna26being about 13 millimeters or smaller. Use of 5.8 GHz also facilitates very small tag designs compared to radio frequency identification (RFID) tags. Thus antenna26may be easily located near the card reader slot. A further advantage of using one of these frequencies is that any rain that enters the card reader slot has little effect on communications between reader20and tags30, since the dielectric constant of water at microwave frequencies is low.

Reader20further includes controller22which controls operation of wireless communication circuitry24and analyzes a reply signal from tag30. Controller22includes a processor, memory, and program and data storage. Controller22executes software for obtaining the tag identifier from the reply signal and comparing a received tag identifier to a reference tag identifier to ensure that tag30is operational and has not been tampered with, damaged or removed. If the tag identifier is encrypted, controller22decrypts the information stored within tag30before comparing in order to more easily detect attempts to copy or replace tag30. When tag30is affixed to or embedded into a card reader guide cover, the comparison also determines whether the card reader guide cover has been moved, replaced or otherwise tampered with. When no reply signal is received or incorrect or no data is received, reader20sets an alarm condition. Reader20may send an alarm message to computer40in response to the alarm condition.

Any foreign object close to the transmission and response paths between antenna26and tag30will change the response signal. Thus, for each tag30, controller22also determines response data (e.g., signal magnitude and phase) from each reply signal and compares received response data to reference response data stored with tag identifiers to ensure that no foreign objects have been inserted close to the transmission and response paths. When no reply signal is received or incorrect or no data is received, reader20sets an alarm condition. Reader20may send an alarm message to computer40in response to the alarm condition.

Insertion of cards and operation of proximate devices, such as a card reader and printer, also change the response signal. Therefore, controller22takes measurements when the card reader, printer, and other devices are not in use and the system is in a quiet state.

Reader20and/or computer40may store reference tag identifiers and reference tag frequency response data. In one example embodiment, computer40stores the reference tag identifiers and reference tag frequency response data and reader20obtains the data from computer40for comparison. The reference data may be captured and stored following installation of reader20and tag30.

Computer40may include an ATM, fuel pump, or other terminal in which reader20is installed. Alternatively, computer40may include a network server which receives communications directly from reader20or through an intermediary computer, such as an ATM, fuel pump, or other terminal in which reader20is installed.

Computer40includes one or more processors, memory, and program and data storage and is configured to execute software necessary to its purpose. Computer40further includes circuitry for connecting to corresponding circuitry in reader20. For example, computer50may include network circuitry, Universal Serial Bus (USB) circuitry and/or Bluetooth standard circuitry.

Computer40and reader20may be configured to encrypt communication between them. This prevents fraudsters from interpreting communications from reader20and from spoofing computer40into accepting false tag data from a reader20that has been tampered with.

With reference toFIG. 2, an example computer40in the form of an automated teller machine (ATM)50is illustrated. ATM50includes a fascia52attached to a chassis78. Fascia52provides a user interface for allowing an ATM customer to execute a transaction.

Fascia52defines an aperture54through which a camera images a customer of the ATM100. Fascia52also defines a number of slots for receiving and dispensing media items and a tray56into which coins can be dispensed. The slots include a statement output slot58, a receipt slot60, a card reader62with a card reader slot64defined by card reader guide cover66, a cash dispense slot68, a cash and check deposit slot70and a branding badge72. The slots and tray are arranged such that the slots and tray align with corresponding ATM modules mounted within the chassis of the ATM.

The fascia52includes an encrypting keyboard74for allowing an ATM customer to enter transaction details. A display76is provided for presenting transaction screens to an ATM customer.

Reader20is located within chassis78. In one example configuration, reader20is located above card reader62.

Reference will now also be made toFIGS. 3 and 4, which are front and rear perspective views, respectively, of example card reader guide cover66. Card reader guide cover66comprises a molded plastics part dimensioned to be accommodated within, and partially protrude through, an aperture in a fascia52.

An example card reader guide cover66includes a molded plastics part dimensioned to be accommodated within, and partially protrude through, an aperture in fascia52. Card reader guide cover66includes three apertured tabs80by which card reader guide cover66is coupled to a rear surface of fascia52.

Card reader slot64extends generally horizontally across card reader guide cover66in the direction of centre line84, from one end86to another end88.

Some card readers require orientation of magnetic stripe cards before insertion. In other card readers, the magnetic stripe may be oriented to the one end86or the other end88. In this example embodiment, a customer must insert a magnetic stripe card with the magnetic stripe facing down and adjacent other end88.

Card reader guide cover66defines a breakout line90extending generally vertically (perpendicular to card reader slot64). Card reader guide cover66also defines a first (lower) protrusion92.

The first (lower) protrusion92includes a planar section94across which the magnetic stripe side of a card passes as the card is inserted. The first (lower) protrusion92also includes an upright section96that extends from the breakout line90to an end surface98. End surface98is spaced from the card slot64to ensure that card does not protrude beyond end surface98when ejected by card reader62.

A magnetic stripe path100is defined on planar section94. This is the portion of the planar section94that the magnetic stripe on a correctly inserted card will be in registration with when the card is inserted or removed by a customer. In this embodiment, the magnetic stripe path100is centered on track two of a magnetic stripe. It is track two that carries the customer account information, so track two is the track that alien readers attempt to read.

The first protrusion92also defines a cavity (best seen inFIG. 4and shown generally by arrow102), which is beneath planar section94and within card reader guide cover66.

Card reader guide cover66defines a second (upper) protrusion104similar to, aligned with, and opposite the first protrusion92.

The second (upper) protrusion104includes a planar section106(best seen inFIG. 4) beneath which a magnetic stripe side of a card passes as the card is inserted. The second (upper) protrusion104also includes an upright section108that extends from the breakout line90to an end surface110. The second protrusion104defines a cavity112above planar section106.

Other card reader guide cover shapes and configurations are also envisioned.

Referring toFIG. 4, an example configuration includes tag30installed in cavity102. Tag is positioned so that the reply signal can be detected without a lot of noise. As the distance between reader20and tag30increases, other factors like antenna polarization, should be considered.

In addition to tag30, other safeguards may also be installed within card reader guide cover66, such as a capacitive sensor.

Tags30may also be positioned in fascia52to detect attempts to install a camera or a keypad overlay to capture pin entry.

Referring now toFIG. 5, an example tamper detection method begins with step120, in which reader20transmits a continuous wave signal.

In step122, if reader20fails to receive a reply signal, operation proceeds to step134. Otherwise, operation continues to step124.

In step124, reader20demodulates the reply signal to obtain a tag identifier. If the tag identifier is encrypted, reader20additionally decrypts the received data to obtain the tag identifier.

In step126, reader20determines frequency response data associated with the reply signal, including signal magnitude and phase.

In step128, reader20obtains a reference tag identifier and reference frequency response data from computer40.

In step130, reader20compares the tag identifier from the reply signal with a reference tag identifier. If the comparison is true, operation continues to step132. Otherwise, operation continues to step134.

In step132, reader20compares the frequency response data to reference frequency response data. If the comparison is true, operation returns to step120. Otherwise, operation continues to step134.

In step134, reader20sends an alarm message to computer40in response to the alarm condition. Operation returns to step120to continue monitoring.

A service organization responsible for monitoring operation of the device may remove the device from service and dispatch a technician to examine the device. When computer40contains the device, the service organization may remove computer40from service.

Tamper detection system10may be used to provide intrusion detection for devices like secure computing devices and safes against enclosure opening and mechanical attacks, like drilling. Tamper detection system10may also be used to protect objects from theft and may be used to locate objects near tag30. Tamper detection system10may further be used to provide product information from a tag30for system integrity checks (authentic components present).

Although the present invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications of the present invention can be effected within the spirit and scope of the following claims.