WO1996008794A1 - Circuit d'identification de code de securite - Google Patents

Circuit d'identification de code de securite Download PDF

Info

Publication number
WO1996008794A1
WO1996008794A1 PCT/US1995/008792 US9508792W WO9608794A1 WO 1996008794 A1 WO1996008794 A1 WO 1996008794A1 US 9508792 W US9508792 W US 9508792W WO 9608794 A1 WO9608794 A1 WO 9608794A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
security code
analog
security
access
Prior art date
Application number
PCT/US1995/008792
Other languages
English (en)
Inventor
Edward C. Leung
Original Assignee
Westinghouse Electric Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric Corporation filed Critical Westinghouse Electric Corporation
Publication of WO1996008794A1 publication Critical patent/WO1996008794A1/fr

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C9/00—Individual registration on entry or exit
    • G07C9/20—Individual registration on entry or exit involving the use of a pass
    • G07C9/27—Individual registration on entry or exit involving the use of a pass with central registration
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C9/00—Individual registration on entry or exit
    • G07C9/20—Individual registration on entry or exit involving the use of a pass
    • G07C9/28—Individual registration on entry or exit involving the use of a pass the pass enabling tracking or indicating presence

Definitions

  • the present invention relates to a security code identification circuit.
  • the card transmits a security code that is read by the reader.
  • This security code typically has an identifi ⁇ cation field that the reader must identify and decode prior to granting access to the location.
  • a known approach uses a security code having two fields that include a preamble and a body.
  • the preamble typically consists of 8 bits and the body of 32.
  • these card readers suffer from two problems. The first is that analog reader components are sensitive to signal fluctuations and the positioning of the access card. The second is the inability to fully discern the preamble and the body due to their mode of analog operation. That is, because the circuit employs analog devices and is very sensitive to card position, the reader does not adequately characterize and store the full transmission and it does not verify the entire security code.
  • the card reader uses only 3 of the 8 preamble bits in order to permit or deny access to the location.
  • An approach is needed that can discern the security code regardless of card position and that fully interprets and evaluates the security access code to provide tamper-resistant access to the secure location.
  • the present invention describes an apparatus for receiving and verifying the whole security code preamble to improve the quality and reliability of security systems.
  • An access card reader includes a receive antenna sensitive to a first signal generated by an access card.
  • a receiver circuit is coupled to the receive antenna to detect an analog second signal in the receive antenna. When the receive antenna is excited, the receiver condi ⁇ tions the analog second signal, and an analog to digital converter converts the second signal into a digital secur ⁇ ity code.
  • a processor determines the validity of the security code.
  • the secur ⁇ ity code includes a plurality of fields including an 8-bit preamble field, a data field and an error detection field.
  • Figure 1 is a schematic diagram of an access card and an access card reader
  • Figure 2 is a graph illustrating bipolar phase shift keyed (BPSK) signal between the access card and the access card reader;
  • BPSK bipolar phase shift keyed
  • Figure 3 depicts a type of security code word information
  • Figure 4 is a schematic diagram of the access card reader of Figure 1;
  • Figure 5 is a flowchart showing the card reader functions;
  • Figure 6 depicts a second type of security code word information;
  • Figure 7 is a graph illustrating quadrature phase shift keyed (QPSK) signal between the access card and the access card reader; and Figure 8 depicts a network version employing the present invention.
  • QPSK quadrature phase shift keyed
  • Figure 1 depicts a first embodiment of the invention showing an access card 20 and an access card reader 10.
  • an oscillator In the access card reader 10, an oscillator generates a 140 KHz signal that is communicated to transmit antenna 12. This signal has enough energy to cause an electro-magnetic field to form in the vicinity of the transmit antenna 12.
  • the access card 20 when it is placed within the vicinity of the card reader 10, receives energy on its receive antenna 22. This energy is accumulated and stored in the card 20, for example, by a diode and capacitor rectifier. The card 20 also uses the 140 KHz oscillating field to clock its circuitry at 70 KHz. Once sufficient energy is stored in the card 20, the card transmitter is activated and an RF security signal is transmitted from the card via transmit antenna 24 at 70 KHz using phase shift keyed (PSK) modulation. The RF security signal is then received by the reader via receive antenna 14.
  • PSK phase shift keyed
  • Receive antenna 14 is coupled to a receiver that conditions the analog security signal, e.g., amplifies and filters the analog security signal.
  • the receiver demodulates the signal according to the type of modulation with which the signal was originally encoded.
  • Figure 2 is a graph illustrating a bipolar phase shift keyed (BPSK) signal transmitted by the access card 20 and received by the access card reader 10.
  • BPSK phase shift keyed
  • This general type of phase shift keyed communication is known in the art and involves the receiver synchronizing up with the carrier and then looking for phase changes that represent data.
  • BPSK there are two states that are represented as "0" and "1.” Each of these states is correlated to a phase of the signal. For example, in-phase represents "0,” and 180° out-of-phase represents "1.”
  • the access card 20 transfers the identifying information to the access card reader 10.
  • the access card reader 10 verifies the security code to grant access to the location, if appropriate.
  • the card reader 10 synchronizes on the first bit transmitted. Then, the card reader interprets the succeeding 7 bits in the prea - ble and verifies the 8-bit preamble field. Thereafter, the card reader 10 receives the 32 bits of data and verifies the 32-bit data field.
  • the security code is received and verified by the access card reader 10.
  • the elements depicted in Figure 4 are those that perform this function.
  • the receive antenna 14 is connected to a receiver 30 that detects a current signal in the receive antenna 14. When current is excited in the receive antenna 14, the receiver 30 amplifies the current signal and filters the current signal by isolating the relevant frequency band of interest that is received from the access card 20.
  • An analog to digital (A/D) converter 40 converts the analog current signal into a digital form -- a digital security code.
  • This converted digital security code is then delivered to a digital signal proces ⁇ sor (DSP) 50 to verify the security code.
  • DSP 50 which has a memory associated therewith, performs a series of functions to verify the preamble and data that consti ⁇ tute the security code word before communicating it to a central processor unit 60.
  • FIG. 5 is a flowchart 70 showing the card reader functions, which are primarily executed by the DSP 50.
  • the card reader has power and is broadcasting energy through transmit antenna 12 to maintain an electromagnetic field in the proximity of the card reader 10.
  • an access card enters the area and is powered up, it transmits a signal that is received on receive antenna 14.
  • the RF amplifier and filter 30 detects energy on the receive antenna 14 amplifies and filters the signal, and the A/D 40 converts the analog signal to digital data.
  • the DSP 50 receives the data and determines if sufficient energy is present in the signal to read the preamble.
  • the DSP 50 begins an integration function that accumulates the data in step 76. Then, in step 78, the DSP 50 performs a threshold comparison between the received data and a predetermined set threshold. If the received data is above the predeter ⁇ mined threshold, step 80 is performed.
  • Step 80 involves detecting the phase of the data signal.
  • the DSP 50 takes the digital samples and sets the initial phase to 0°. This initial setting permits the DSP to compare subsequent phases against a known initial phase. As additional data is received, the DSP 50 compares the phase of the signal to the initial 0° phase and assigns data values to the phases where in-phase is a "0" and out- of-phase is a "1. " A sliding cross-correlation is performed between the received data and a valid preamble in step 82. This permits the DSP 50 to verify the preamble by comparing the received data against a valid preamble. If the preamble is verified, step 84 is performed which informs the CPU 60 of the verification.
  • the security system permits the user to enter the location by, for example, unlocking the door.
  • This system can also monitor the comings and goings of persons at a guarded gate by recording their personalized data encoded on their access card in the security code word.
  • the procedure outlined above has advantages over those previously developed. For one, the signal to noise ratio can be low since the digital signal processor is comparing the received code against a known valid code. That is, a cross-correlation between a received code and a known code permits a low signal to noise ratio signal to be properly interpreted.
  • the access card reader 10 can properly interpret the access card 20 in a variety of positions that prior techniques may not have properly interpreted.
  • the DSP 50 has a memory associated therewith, the DSP can retain the incoming security code as well as a valid code to verify the entire preamble and can correlate the entire received signal against a valid security code.
  • the following is an example of an operational configuration.
  • the access card reader generates a field signal at 140 KHz on the card reader transmit antenna.
  • the access card generates a transmission signal with a 70 KHz carrier that is received by the card reader.
  • the bit data rate is 8750 Hz so that each bit contains 8 carrier cycles.
  • the data is phase encoded at 0° for a "0" and 180° for a "1."
  • the A/D converter digitizes the received signal at a rate of 280K samples per second with 8 bits or resolution.
  • the DSP such as the Analog Devices ADSP2115, running at 64 MHz obtains the in-phase and out-of-phase values of the digitized signal.
  • the DSP also performs integration of the digitized data and determines if the signal energy is above a predetermined threshold.
  • the DSP decodes the preamble data and, when there is a valid preamble match, the DSP verifies the preamble transmission and instructs the A/D converter to send the tag data, which the DSP then decodes.
  • Figure 6 depicts a second type of security code word information.
  • This code word includes a plurality of fields for a security code word that identify a particular characteristic of the card.
  • a mode field incorporates various operational parameters of the system, and parity and checksum fields incorporate error detection and correc- tion.
  • any field can be incorpo ⁇ rated into the code word so long as the card has sufficient energy to transmit the data.
  • Figure 6 shows a blank field of 32 bits.
  • this field is intended to provide a no-transmit period of time in which the DSP 50 can verify the preamble before recording the data -- actually make the decision on the fly whether to record the data.
  • This field can also be used, in another aspect of the invention, to permit the card to recharge in order to extend the security code word length. That is, if a card needs extra energy to transmit a long code word, a pre ⁇ determined no-transmit period can permit the card to recharge before retransmitting the remainder of the code word.
  • Figure 7 is a graph illustrating quadrature phase shift keyed (QPSK) signal between the access card and the access card reader. In this type of transmission, four different phases represent four different data nibbles.
  • QPSK quadrature phase shift keyed
  • FIG. 8 depicts a network version 90 employing the present invention. This configuration demonstrates how the invention might be deployed in a building or at a site. A plurality of card readers 92, 94, 96 are placed at various locations around the site, such as at the doors or security stations. When a person seeks entrance to the site, he places his access card near one of the card readers and the card reader opens the door, if appropriate.
  • the central computer 98 can verify that the person is authorized to enter the location and log the entry location, date and time.
  • the central computer 98 can also monitor a person's movements through various locations at the site and can log the person's entrance and exit from the site.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Theoretical Computer Science (AREA)
  • Lock And Its Accessories (AREA)

Abstract

Lecteur de carte d'accès qui comporte une antenne de réception (14) sensible à un premier signal généré par une carte d'accès. Un circuit récepteur (30) est couplé à l'antenne de réception pour détecter un second signal analogique dans l'antenne de réception. Lorsque l'antenne de réception est excitée, le récepteur traite le second signal analogique et un convertisseur analogique-numérique (40) convertit le second signal en code de sécurité numérique. Un processeur (50) détermine ensuite la validité du code de sécurité. Selon un aspect de la présente invention, le code de sécurité inclut une pluralité de champs, dont un champ préambule à 8 bits, un champ de données et un champ de détection d'erreurs.
PCT/US1995/008792 1994-09-12 1995-07-17 Circuit d'identification de code de securite WO1996008794A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US30434694A 1994-09-12 1994-09-12
US08/304,346 1994-09-12

Publications (1)

Publication Number Publication Date
WO1996008794A1 true WO1996008794A1 (fr) 1996-03-21

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Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6068627A (en) * 1997-12-10 2000-05-30 Valleylab, Inc. Smart recognition apparatus and method
EP1363400A3 (fr) * 2002-05-18 2005-08-10 K.A. SCHMERSAL GmbH & Co. Interrupteur de sécurité
US7104834B2 (en) 2003-02-20 2006-09-12 Sherwood Services Ag System and method for connecting an electrosurgical instrument to a generator
US8653994B2 (en) 2012-03-21 2014-02-18 Covidien Lp System and method for detection of ADC errors
US8966981B2 (en) 2003-10-30 2015-03-03 Covidien Ag Switched resonant ultrasonic power amplifier system
US9113900B2 (en) 1998-10-23 2015-08-25 Covidien Ag Method and system for controlling output of RF medical generator
US9119624B2 (en) 2006-04-24 2015-09-01 Covidien Ag ARC based adaptive control system for an electrosurgical unit
US9186200B2 (en) 2006-01-24 2015-11-17 Covidien Ag System and method for tissue sealing
US9271790B2 (en) 2007-09-21 2016-03-01 Coviden Lp Real-time arc control in electrosurgical generators
US9474564B2 (en) 2005-03-31 2016-10-25 Covidien Ag Method and system for compensating for external impedance of an energy carrying component when controlling an electrosurgical generator
US9522032B2 (en) 2005-10-21 2016-12-20 Covidien Ag Circuit and method for reducing stored energy in an electrosurgical generator
US9529025B2 (en) 2012-06-29 2016-12-27 Covidien Lp Systems and methods for measuring the frequency of signals generated by high frequency medical devices
US9636165B2 (en) 2013-07-29 2017-05-02 Covidien Lp Systems and methods for measuring tissue impedance through an electrosurgical cable
US9642665B2 (en) 2006-01-24 2017-05-09 Covidien Ag Method and system for controlling an output of a radio-frequency medical generator having an impedance based control algorithm
WO2017137265A1 (fr) * 2016-02-09 2017-08-17 Izettle Merchant Services Ab Terminal lecteur de carte avec antenne sans contact externe
US9872719B2 (en) 2013-07-24 2018-01-23 Covidien Lp Systems and methods for generating electrosurgical energy using a multistage power converter
US11763290B2 (en) 2017-03-20 2023-09-19 Paypal, Inc. Point of sale system and method for contactless payment

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3305685A1 (de) * 1982-03-05 1983-09-15 Sensormatic Electronics Corp., 33441 Deerfield Beach, Fla. Mit kodierten erkennungsmarken arbeitendes durchgangsueberwachungssystem
EP0306598A2 (fr) * 1987-09-08 1989-03-15 Clifford Electronics, Inc. Systèmes d'accès avec commande à distance électroniquement programmables
WO1991006926A1 (fr) * 1989-10-31 1991-05-16 Security Dynamics Technologies, Inc. Methode et dispositif destines a assurer la securite de l'identification et de la verification

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3305685A1 (de) * 1982-03-05 1983-09-15 Sensormatic Electronics Corp., 33441 Deerfield Beach, Fla. Mit kodierten erkennungsmarken arbeitendes durchgangsueberwachungssystem
EP0306598A2 (fr) * 1987-09-08 1989-03-15 Clifford Electronics, Inc. Systèmes d'accès avec commande à distance électroniquement programmables
WO1991006926A1 (fr) * 1989-10-31 1991-05-16 Security Dynamics Technologies, Inc. Methode et dispositif destines a assurer la securite de l'identification et de la verification

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7044949B2 (en) 1997-12-10 2006-05-16 Sherwood Services Ag Smart recognition apparatus and method
US6402743B1 (en) 1997-12-10 2002-06-11 Sherwood Services Ag Smart recognition apparatus and method
US6685701B2 (en) 1997-12-10 2004-02-03 Sherwood Services Ag Smart recognition apparatus and method
US6068627A (en) * 1997-12-10 2000-05-30 Valleylab, Inc. Smart recognition apparatus and method
US9113900B2 (en) 1998-10-23 2015-08-25 Covidien Ag Method and system for controlling output of RF medical generator
US9168089B2 (en) 1998-10-23 2015-10-27 Covidien Ag Method and system for controlling output of RF medical generator
EP1363400A3 (fr) * 2002-05-18 2005-08-10 K.A. SCHMERSAL GmbH & Co. Interrupteur de sécurité
US7104834B2 (en) 2003-02-20 2006-09-12 Sherwood Services Ag System and method for connecting an electrosurgical instrument to a generator
US8966981B2 (en) 2003-10-30 2015-03-03 Covidien Ag Switched resonant ultrasonic power amplifier system
US9768373B2 (en) 2003-10-30 2017-09-19 Covidien Ag Switched resonant ultrasonic power amplifier system
US9474564B2 (en) 2005-03-31 2016-10-25 Covidien Ag Method and system for compensating for external impedance of an energy carrying component when controlling an electrosurgical generator
US11013548B2 (en) 2005-03-31 2021-05-25 Covidien Ag Method and system for compensating for external impedance of energy carrying component when controlling electrosurgical generator
US9522032B2 (en) 2005-10-21 2016-12-20 Covidien Ag Circuit and method for reducing stored energy in an electrosurgical generator
US9186200B2 (en) 2006-01-24 2015-11-17 Covidien Ag System and method for tissue sealing
US10582964B2 (en) 2006-01-24 2020-03-10 Covidien Lp Method and system for controlling an output of a radio-frequency medical generator having an impedance based control algorithm
US9642665B2 (en) 2006-01-24 2017-05-09 Covidien Ag Method and system for controlling an output of a radio-frequency medical generator having an impedance based control algorithm
US9119624B2 (en) 2006-04-24 2015-09-01 Covidien Ag ARC based adaptive control system for an electrosurgical unit
US9271790B2 (en) 2007-09-21 2016-03-01 Coviden Lp Real-time arc control in electrosurgical generators
US8653994B2 (en) 2012-03-21 2014-02-18 Covidien Lp System and method for detection of ADC errors
US10338115B2 (en) 2012-06-29 2019-07-02 Covidien Lp Systems and methods for measuring the frequency of signals generated by high frequency medical devices
US10073125B2 (en) 2012-06-29 2018-09-11 Covidien Lp Systems and methods for measuring the frequency of signals generated by high frequency medical devices
US9529025B2 (en) 2012-06-29 2016-12-27 Covidien Lp Systems and methods for measuring the frequency of signals generated by high frequency medical devices
US9872719B2 (en) 2013-07-24 2018-01-23 Covidien Lp Systems and methods for generating electrosurgical energy using a multistage power converter
US11135001B2 (en) 2013-07-24 2021-10-05 Covidien Lp Systems and methods for generating electrosurgical energy using a multistage power converter
US9655670B2 (en) 2013-07-29 2017-05-23 Covidien Lp Systems and methods for measuring tissue impedance through an electrosurgical cable
US9636165B2 (en) 2013-07-29 2017-05-02 Covidien Lp Systems and methods for measuring tissue impedance through an electrosurgical cable
WO2017137265A1 (fr) * 2016-02-09 2017-08-17 Izettle Merchant Services Ab Terminal lecteur de carte avec antenne sans contact externe
CN108604287A (zh) * 2016-02-09 2018-09-28 伊兹特商户服务公司 具有外部非接触式天线的读卡器终端
EP3783523A1 (fr) * 2016-02-09 2021-02-24 PayPal, Inc. Terminal lecteur de carte avec antenne sans contact externe
US11636461B2 (en) 2016-02-09 2023-04-25 Paypal, Inc. Card reader terminal with external contactless antenna
US12045801B2 (en) 2016-02-09 2024-07-23 Paypal, Inc. Card reader terminal with external contactless antenna
US11763290B2 (en) 2017-03-20 2023-09-19 Paypal, Inc. Point of sale system and method for contactless payment

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