PRODUCTS

Field of the invention The present invention relates to a device and a method for identifying electronic/electric products, more specifically a device and a method for genuine-and-counterfeit determination, as well as an electronic control system based on measurements of particular physical features of electronic/electric products and uniqueness of these physical features.

Background of the invention

Nowadays, many electronic/electric product manufacturers of known brands enable customers or merchants to distinguish genuine products from counterfeits. A typical technique is the use of anti-counterfeit labels. In this application, electronic/electric products comprise common electric products, i.e. electro-optical devices and dynamo-electric devices working under "heavy current" conditions, such as electric lights, electromotors, as well as common electronic products, i.e. telecom devices working under weak current conditions, such as telephones, and MP3 players.

Anti-counterfeit labels are generally stuck onto the outer packaging, such as wrapping boxes, of electronic/electric products. A typical example is the Security Label. Before sale, the tip reading "uncovering the surface layer and dialing 800*** or sending SMS to 9588*** for identification" on the Security Label is covered by an opaque slip cover. After a product has been bought, a customer can uncover the opaque slip cover and subsequently dial the free phone number or send an SMS message, so as to determine whether the product from the manufacturer or the appointed institution is genuine or a counterfeit. It is a pity that a counterfeiter can easily cheat customers by means of copying a Security

Label and labeling a fake 800 Call Center.

Another type of existing anti-counterfeit labels, namely Winsafe Coupon, has integrated eight advanced anti-counterfeit techniques, such as UV image, anti-Xeroxing, and anti-scanning, in order to avoid malicious attack. i However, fake labels with five techniques of the Winsafe Coupon have appeared. Genuine products could hardly be distinguished from counterfeits with the naked eye, and also customers could hardly distinguish genuine anti-counterfeit labels from fakes.

Besides, it is a common disadvantage of all anti-counterfeit labels that they are attached outside an electronic/electric product, even on its package, which make them easily removable so that the electronic/electric product cannot be identified.

In existing electronic control systems such as electronic locking systems, all electronic keys and locks are provided with circuits inside. When an electronic key tries to open an electronic lock in the contact or contactless mode, it will exchange electric signals so as to achieve authentication.

However, the electronic locking systems mentioned above have a poor resistance against malicious attack, mainly because an electronic key based on the technique can be easily counterfeited and will not be detected by an electronic lock, because a counterfeiter may absolutely make a fake electronic key generating and emitting a signal which is similar enough to, or is even the same as, that of an allowable one with existing technologies.

Likewise, the authentication systems for bank cards have the same potential safety hazard as electronic locking systems.

Object and summary of the invention It is an object of the present invention to provide novel detection devices and methods determining whether an electronic/electric product is genuine or a counterfeit, the detection devices and methods identifying electronic/electric products by using their inherent and unique impedance characteristics.

To this end, the present invention provides a detection device determining whether an electronic/electric product is genuine or a counterfeit, the device comprising: a first unit for acquiring information of said electronic/electric product relating to its radio input impedance, wherein said information is measured on the basis of feedback of said electronic/electric product in response to a radio input signal; a second unit for identifying said electronic/electric product by comparing the acquired information with prestored assistant information of the classification of said electronic/electric product relating to the radio input impedance, and determining whether the relationship between the acquired information and said prestored assistant information satisfies a predefined condition.

The present invention also provides a method of determining whether an electronic/electric product is genuine or a counterfeit, the method comprising the steps of: acquiring information of said electronic/electric product relating to its radio input impedance, wherein said information is measured on the basis of feedback of said electronic/electric product in response to a radio input signal; identifying said electronic/electric product by comparing the acquired information with prestored assistant information of the classification of said electronic/electric product relating to the radio input impedance, and determining whether the relationship between said acquired information and said prestored assistant information satisfies a predefined condition.

It is a further object of the present invention to provide an electronic control system and a method of realizing such a system, the system and method being able to improve the precision of identifying an electronic controller to an electronic trigger, so as to make it more difficult to counterfeit the electronic trigger.

To this end, the present invention provides an electronic controller comprising: a plurality of contact terminals of a control portion electrically contactable to an electronic trigger; a storage storing impedances of each allowable electronic trigger and taking them as allowable triggering impedances; an impedance detector coupled to said plurality of contact terminals of the control portion, used for detecting the impedance of an electronic trigger when said electronic trigger is electrically contacted to said electronic controller; a processor for comparing said detected impedance of said electronic trigger with a prestored, at least one allowable triggering impedance, and for controlling so as to execute a corresponding triggering operation when the differential between said detected impedance of said electronic trigger and any of the prestored, allowable triggering impedances is below a predefined threshold.

The present invention further provides an electronic control system comprising an electronic controller as mentioned above, and at least one allowable trigger, wherein each allowable trigger comprises an impedance element set, said impedance element set comprising at least one impedance element and being coupled to a plurality of contact terminals of the control portion of said allowable trigger for electrically contacting said electronic controller.

To this end, the present invention further provides a method of realizing an electronic control system, the method comprising the steps of: providing an electronic controller as mentioned above; providing at least one allowable trigger, wherein each allowable trigger comprises an impedance element set, said impedance element set comprising at least one impedance element and being coupled to a plurality of contact terminals of the control portion of said allowable trigger for electrically contacting said electronic controller.

The detection devices and methods determining whether an electronic/electric product is genuine or a counterfeit, the electronic control system and its method of realization provided by the present invention make use of mostly ignored inherent and unique impedance characteristics of individual electronic/electric products at a given measurement port in a selected frequency band, so as to greatly improve anti-counterfeit measures.

Brief description of the drawings Other features, objects and advantages of the present invention are apparent from and will be elucidated with reference to the following detailed description of non-limiting embodiments, given by way of example, and the accompanying drawings, in which:

Fig.l is a sketch of the inside structure of a CFL;

Figs.2a-2b illustrate the framework chart of systems for anti-counterfeit of electronic/electric products according to an embodiment of the present invention;

Fig.3 shows a detection device for determining genuineness or counterfeit of electronic/electric products according to an embodiment of the present invention;

Fig.4a illustrates the S parameter of the detection device 221 as shown in Fig.2b according to a preferred embodiment of the present invention; Fig.4b illustrates the S parameter of the device 211 as shown in Fig.2b according to a preferred embodiment of the present invention;

Fig.5 illustrates the relationship between the measurement results of the detection device 221 and the device 211, as shown in Fig.2b, with information of the same electronic/electric product relating to its radio input impedance, according to a preferred embodiment of the present invention;

Fig.6a illustrates an electronic key according to an embodiment of the present invention; and Fig.6b illustrates an electronic lock according to an embodiment of the present invention. Identical or similar reference signs refer to the same or similar step features/means (modules).

Description of embodiments

Fig.1 is a sketch of the inside structure of a CFL. The detection devices and methods for determining genuineness or counterfeit of electronic/electric products provided by the present invention will be described below, mainly taking CFL as an example. It will be evident to those skilled in the art that the protective scope of the present invention is not limited to these embodiments. The present invention can be applied to any electronic/electric product that is capable of responding to radio input signals and providing feedback signals, including but not limited to electronic/electric products provided with inverter circuits, such as bridge/half-bridge rectifiers.

As mentioned above, existing techniques employ anti-counterfeit labels for anti-counterfeit of electronic/electric products. Since an anti-counterfeit label is appended to a finished electronic/electric product and has nothing to do with the electronic/electric product itself. Moreover, it can be easily copied and removed. The present invention is therefore based on the recognition that genuineness or counterfeit of an electronic/electric product can be determined on the basis of an inherent and unique electrical characteristic of each electronic/electric product, a typical example of which is radio input impedance.

In the radio band, the radio input impedance Z _in = R + jX measured at electric contact parts 11 and 12 of the lamp end of a fluorescence lamp depends on the values of many elements on the circuit board, as well as on the size and shape of the electrolytic capacitor C4 commonly used for filtering with a relatively high capacitance and a big volume, leads connecting to the inside circuit from electric contact parts 11 and 12, and the distributed inductance and capacitance of the circuit board and metal construction (not shown in Fig.l).

The radio input impedance of the fluorescence lamp 1 is influenced by many parameters. Consequently, there are absolutely no two individual fluorescence lamps with the same radio input impedance because of the following aspects of randomness:

1. fluorescence lamps differ from each other in length of leads, shape and size and even in the installation position of their elements, because they are randomly chosen and assembled on the assembly line;

2. many elements on the circuit board, such as C4, Cl, R2, are chosen in accordance with their marked values during manufacture of the fluorescence lamps. Actually, the real parameters of these elements would rationally distribute in an allowable range around values rather than in a range just equal to the marked values; 3. distance and other factors among elements on the circuit board of different fluorescence lamps are variable in a relatively large range rather than being constant;

4. once products are fully assembled, the above-mentioned differences are inherent in products and will not be affected by transportation, storage, or even usage, unless these products are disassembled or reassembled after disassembly. Generally, these differences between different fluorescence lamps will not affect user experience. For example, it will be evident to those skilled in the art that, for two resistors with a marked value of one million ohms and an allowable error of one in a thousand, assembled in two fluorescence lamps, one might have a resistance of 0.999 million ohms, whereas the other might have a resistance of 1.001 million ohms. Differences of brightness of two fluorescence lamps caused by such a difference of resistance can hardly be recognized with the naked eye. Moreover, users do not care about such differences, so that manufacturers do not need to care about such differences either and even much less need to overcome them.

However, unique electrical characteristics of electronic/electric products, such as radio input impedance, can exactly distinguish an electronic/electric product, so that it is used in the present invention for determining genuineness or counterfeit of a product. This important information has been ignored all along. On the one hand, there are differences in different electronic/electric products of the same type and, on the other hand, differences between electronic/electric products of the same type based on the same design, such as fluorescence lamps of certain types designed and produced by company A and fluorescence lamps of this type designed by company A and produced by company B, C, D, should fall within a certain range.

Figs.2a-2b illustrate the framework chart of anti-counterfeit systems for electronic/electric products according to an embodiment of the present invention. Fig.3 illustrates a detection device, used in a system as illustrated in Figs.2a-2b, for determining genuineness or counterfeit of electronic/electric products according to an embodiment of the present invention.

Referring to Fig.2a, the factory 21 accommodates at least one device 211, as well as a corresponding database 212 and a processing center 213. The structure of the device 211 will be described in detail below. Before leaving the factory, each electronic/electric product will be measured by the device 211, and the measured information of each electronic/electric product relating to its radio input impedance will be stored in the database 212 in accordance with a predefined strategy. Stored information associated with the information relating to the radio input impedance optionally comprises the product type, the manufacturer, the production date and/or site, etc. For some types of electronic/electric products such as fluorescence lamps of a certain type, information relating to the radio input impedance stored in the database 212 is preferably that obtained by the device 211 measuring a great many genuine products of this type on the basis of a training mechanism. This training mechanism may adopt a common characteristic extracting method, such as a clustering method. If the identification of electronic/electric products is not sensitive to data size and processing speed, the database 212 can store information of all genuine products coming on the market and relating to their radio input impedance. When an electronic/electric product is to be identified, the measured information of the electronic/electric product relating to its radio input impedance is compared with prestored information of each genuine product relating to the radio input impedance, so as to determine whether it is genuine. This has the advantage that not only the genuineness or counterfeit of the product can be determined but also the individual information of the product can be recognized in future identifications.

The circulation channel 22 of electronic/electric products, such as storage or transport belts, is provided with a detection device 221 ', whose structure is illustrated in Fig.3 and which is used to determine whether a product is genuine or a counterfeit. The detection device 221 ' measures information of corresponding electronic/electric products relating to their radio input impedance, and feeds the measurement result back to the processing center 213 in a wired or wireless manner. The processing center 213 compares the measurement result with the information of genuine products stored in the database 212 relating to their radio input impedance, and identifies the product as a genuine one when the relationship between the measured information and the prestored information satisfies a predefined condition, and, in contrast, identifies the product as a counterfeit when the relationship between the measured information and the prestored information does not satisfy the predefined condition.

Similarly, a point-of-sale terminal of the electronic/electric product, such as a supermarket 23, is also provided with a detection device 231 ' used to determine whether a product is genuine or a counterfeit. The detection device 231 ' measures the information of an electronic/electric product relating to its radio input impedance, and connects to the processing center 213 through a wired or wireless link, similarly as the device 221 '. The processing center 213 performs a comparison by using the information stored in the database 212, so as to determine whether the product is genuine or a counterfeit. As compared to the system illustrated in Fig.2a, the detection devices 221 and 231 are further provided with databases 2211 and 2311, respectively. Hence, the detection devices 221 and 231 can make an elementary identification depending on the information of genuine products stored locally after the information of an electronic/electric product relating to its radio input impedance has been measured. If the electronic/electric product to be identified does not match any information of genuine products stored locally, a request may be sent to the processing center 213 to perform an inquiry and comparison in the database 212, which stores more information, and finally obtains the genuineness identification result of the electronic/electric product and feeds it back to the detection device 221 or 231. Of course, if the databases 2211 and 2311 are largely congruous with the database 212, the detection devices 221 and 231 can directly identify an electronic/electric product as a counterfeit, i.e. it is not genuine, after the local identification result has been obtained, without asking for identification from the remote processing center 213. In this situation, the processing center 213 does not even need to have the function of determining the genuineness or counterfeit of an electronic/electric product, because this function is distributed at each detection device, such as the detection devices 221 and 231.

It will be evident to those skilled in the art that, as compared to a system as illustrated in

Fig.2b, the detection devices in a system as illustrated in Fig.2a, set in circulation channels and supermarkets, have a simpler structure and lower cost since they only need to measure the information of an electronic/electric product relating to its radio input impedance. Accordingly, because all identifications are performed by the uniform processing center, the detection devices set in circulation channels and supermarkets need to frequently exchange information with the processing center. With a view to the processing capability of the processing center and other factors such as transmission condition of the Internet, systems as illustrated in Fig.2a might be in the shade in terms of response speed as compared to those illustrated in Fig.2b.

Correspondingly, in a system as illustrated in Fig.2b, all detection devices set in circulation channels and supermarkets can determine relatively independently whether an electronic/electric product is genuine or a counterfeit. Therefore, they have to be provided with at least a small database memorizer and processor for identification, so that the device cost is relatively high. In this situation, these devices might perform better in response speed since they do not need to frequently exchange information with the processing center.

The structures of the detection devices for determining genuineness or counterfeit of electronic/electric products and the corresponding method steps will be described below with reference to non-limiting embodiments of the present invention. In Fig.3, the detection device 231 as illustrated in Fig.2b is taken as an example. A fluorescence lamp purchased by a customer in a market is taken as an example of the electronic/electric product to be identified.

The fluorescence lamp 318 connects to the detection device 231 via the receptacle 319 on this device. The radio signal source 311 generates a radio signal such as a wide -band sweeping signal within a frequency band of, for example, IkHz to 20GHz, preferably 50MHz to 1.2GHz. The radio signal enters the power divider 312 and is divided into two branches of radio signals 324 and 326 in accordance with a predefined power division ratio. In this non-limiting embodiment, the power division ratio is 1 : 1. In this embodiment, the radio signal source 311 and the power divider 312 constitute a fourth unit.

The radio signal 324 will be used as the radio input signal of the fluorescence lamp 318, and the radio signal 326 will be used as a reference signal, whose function will be described below.

The radio signal 324 passes through a directional coupler 323 and is decomposed into two parts in accordance with a predefined ratio. One part becomes the radio input signal 321 and is imported to the fluorescence lamp 318; the other part enters the matched load 320 and is absorbed without reflection. As mentioned above and as evident to those skilled in the art, along with the excitation of the radio signal, many factors in the structure of the fluorescence lamp 318 as illustrated in Fig.l, such as values and shapes of elements, layout of the circuit board, leads and metal construction, will contribute to the information relating to its radio input impedance. The radio input signal 321 enters the fluorescence lamp 318 and a feedback signal 322 will be produced. The feedback signal 322 passes through the directional coupler 323 and is also decomposed into two parts in accordance with the predefined ratio. One part enters the comparator 313, such as a phase/amplitude comparator. Besides, the reference signal 326 generated by way of power division also enters the comparator 313. The comparator 313 compares the two signals at each frequency point one by one in the frequency band of the signal source, i.e. it calculates the amplitude ratio and phase difference between signal 322 and signal 326, so as to acquire a ratio and phase signal. This ratio and phase signal can be denoted as and is supplied to the ano log-to-digital (AJO) converter 314.

The radio input impedance of the fluorescence lamp 318 may be alternatively denoted as Z _jn = R + jX , and the ratio and phase signal acquired by the comparator 313 may be denoted as . wherein is a complex number comprising the modulus and the phase , the relationship between and Z _1n being:

wherein Z _c is the impedance of the measuring system, generally 50 ohms. Formula (0) shows the relationship of equivalence between and Z _1n . The information relating to the radio input impedance can be embodied as a curve of at least one of the following items plotted against frequency in the frequency band of the radio signal generated by the radio signal source 311 : R , the real part of the complex impedance '" ;

X , the imaginary part of the complex impedance '" ;

\Z _m \, the modulus of the complex impedance ^m ;

Zm, the phase of the complex impedance ^m ; I |, the modulus of ;

, the phase of

The relationship between the information relating to the radio input impedance acquired by the comparator and frequency can refer to the real line 52 in Fig.5, wherein the vertical axis in Fig.5 denotes \Z _m \, the modulus of ^m . The ratio and phase signal will be supplied to the A/D converter 314 by the comparator 313, and the A/D-converted information is used for comparison with the prestored information relating to the input impedance. It will be evident to those skilled in the art that information relating to input impedance prestored in the database memorizer 317 (hereinafter referred to as memorizer 317 for short) should at least partly match the ratio and phase signal acquired by the comparator 313, i.e. when the comparator 313 acquires the curves of the two items R, X plotted against frequency, there is at least information of R or X prestored in the memorizer 317 for comparison. The comparator 313 and the A/D converter 314 then realize the function of the fifth unit, and the fourth and fifth units jointly realize the function of the first unit.

The decision unit 315 makes a comparison and a decision based on the information stored in the memorizer 317 and the information provided by the A/D converter so as to obtain the decision result of whether the fluorescence lamp to be identified is genuine. Without loss of generality, the decision unit 315 can perform the decision based on a least mean square error algorithm, shown as formula (1): wherein N is the sample number of the difference signal such as the modulus signal of the

2 radio input impedance ^m of the fluorescence lamp 318 in the frequency band of the radio input signal 324 or 321, X ₁ is the i-th sample value of the modulus signal of the radio input impedance ^m of the fluorescence lamp 318, and y _τ is the modulus value of the i-th sample of the standard radio input impedance of the type of this electronic/electric product such as an XXXX-type fluorescence lamp produced by company A, and CJ is a variance predetermined on the basis of a training mechanism, and T is a threshold also predetermined on the basis of a training mechanism. In this embodiment, the memorizer 317 can store a set of discrete modulus values of the radio input impedance of each genuine fluorescence lamp of the XXXX type produced by company A in the above-mentioned frequency band, for example, y _{i k} ,i = \ ...N,k = \ ...M , wherein y ' denotes the modulus value of the radio input impedance of the k-th fluorescence lamp at the i-th sample (frequency point). Therefore, the decision unit 315 introduces prestored sets of discrete modulus values of each genuine fluorescence lamp and the discrete signal X ₁ (I...N) provided by the A/D converter into the left part of formula (1), and compares the result with ^τ , till formula (1) is satisfied or till corresponding prestored discrete modulus values of all genuine fluorescence lamps are calculated, and identifies the fluorescence lamp 318 as a genuine product if formula (1) is satisfied or, in the opposite case, as a non-genuine or counterfeit product.

Alternatively, the memorizer 317 can also store a set of discrete modulus values of the radio input impedance acquired on the basis of the training mechanism, wherein this set of values is commonly used by all genuine fluorescence lamps of the XXXX type produced by company A, so that the decision unit 315 needs only one judgment to come to the conclusion whether the fluorescence lamp to be identified is genuine.

Those skilled in the art will appreciate from the above description that the detection devices 221, 231 can be used to determine genuineness or counterfeit of many kinds of electronic/electric products, which may be many types of fluorescence lamps produced by company A, but also many types of fluorescence lamps and many kinds of other electronic/electric products, such as shavers. If used to determine genuineness or counterfeit of many kinds of electronic/electric products, the detection device preferably further comprises a unit for distinguishing the category of the electronic/electric products to be identified, such as a bar code scanner, which is not illustrated in Fig.3. The bar code scanner supplies the result, which it scans, to the decision unit 315 which can rapidly determine useful prestored information for judgment in the memorizer 317.

According to a variant of the embodiment described above, even if a detection device is used to determine genuineness or counterfeit of many kinds of electronic/electric products, it is of course not always provided with a unit for distinguishing the category of the electronic/electric product to be identified. The decision unit 315 or other units not illustrated in Fig.3 can parse the discrete signal provided by the A/D converter 314 and analyze its characteristic so as to find useful information components in a large amount of prestored information in accordance with the analyzed characteristic. This mechanism is generally established under the precondition that information relating to radio input impedance, such as modulus and phase, of different kinds of electronic/electric products is relatively distinct in at least a sub-band of the above-mentioned frequency band.

The decision unit 315 or the combination of the decision unit 315 and the memorizer 317 realizes the function of a second unit.

After the detection device 231 has acquired the result of whether the fluorescence lamp 318 is genuine or not, the result is informed to the user of the detection device 231, such as an employee of a supermarket or a customer, via an indicator 316. The indicator 316 can be embodied as a display or a loudspeaker. Of course, the judgment result of the decision unit 315 requires conversion so as to form an audio/video signal which is usable for the indicator 316 and can be realized by those skilled in the art by means of well-known techniques, which will not be further described.

In the structure of the device 211 in the factory 21, the decision unit 315, the indicator 316 and the memorizer 317 illustrated in Fig.3 can be omitted in this device 211, because it only needs to acquire information of electronic/electric products relating to radio input impedance and does not need to determine genuineness or counterfeit of such products. Of course, there should still be a database 212 for storing the information obtained, through measurement, by the device 211 in the factory 21.

If none of the detection devices in the supermarket and the circulation channel is provided with a database memorizer, the processing center 213 in the factory 21 needs to take on the task of determining genuineness or counterfeit of an electronic/electric product. In this situation, the radio input impedance of an electronic/electric product is acquired by the detection devices in the supermarket and the circulation channel. Each detection device degenerates to a first unit as mentioned above, whereas the processing center 213 becomes a detection device as mentioned above, acquires measured radio input impedance-related information depending on the exchange with other detection devices, and compares it with the prestored information so as to determine whether the electronic/electric product to be identified is genuine.

For the sake of conciseness, other units in the detection device 231 are not illustrated in Fig.3, such as the power supply unit and its specific composition, as well as the user interface and its special composition. However, those skilled in the art can realize these units (not shown) by means of techniques well-known in the art, and this omission in the Figure does not affect the clear description of the essential matter of the present invention.

The detection devices for identifying an electronic/electric product as being genuine or counterfeit and corresponding methods have been described hereinbefore. Some preferred embodiments of the present invention will be described below. As mentioned above, even for electronic/electric products of the same category, there are larger or smaller differences between their radio input impedances, and even the radio characteristics of electronic/electric products of the same category produced in the same factory will differ. The reasons for these differences are similar to the content described above with reference to the inside structure of a fluorescence lamp. These characteristics will be added to the read-out value in the measurement.

As the radio characteristics of detection devices for determining genuineness or counterfeit of the same category may differ, it is likely that the acquired read-out value of the radio input impedance of the detection devices 221 and 231 relating to the same electronic/electric product may differ, so that, due to such a difference, the detection device 221 will identify this product as a genuine product, whereas detection device 231 will identify it as a counterfeit product.

To avoid the above-mentioned situation, and taking Fig.2b as an example, each device having the function of measuring the input impedance of an electronic/electric product can preferably be jointly managed. In other words, in accordance with the relationship between the devices, the results acquired by all other devices will be standardized in accordance with the measurement result of certain devices, or the results acquired by all devices will be standardized in accordance with a predefined value. The above-mentioned standardization process is referred to as calibration.

According to a preferred embodiment of the present invention, the detection devices 231 and 221 will be standardized in accordance with the device 211. The calibration of the detection device 221 with respect to the device 211 is taken as an example below.

Fig.4b illustrates the S parameter of the device 211, wherein _A denotes the information of the fluorescence lamp 318 relating to its radio input impedance acquired by the device 211, comprising at least one of its real part, imaginary part, modulus and phase, or the equivalent Z _1n . According to Fig.4a and based on related well-known definitions of the S parameter, the following formulas can be derived:

wherein the physical significance of F is the objectively existent nature impedance of the fluorescence lamp 318, i.e. the value read by a perfect detection device without interference.

Furthermore, Fig.4b illustrates the dispersion parameter of the detection device 221, wherein F _B denotes information of the fluorescence lamp 318 relating to its radio input impedance acquired by the device 221.

11 O " ₁ 1 ₉ 2 D ofl

1 "22 can be regarded as a transition matrix denoting the difference between the measurement results of the detection device 221 and the device 211.

According to Fig.4b and based on related well-known definitions of the S parameter, the following formulas can be derived:

The following formula can be derived by combining formulas (2) to (11):

It will be evident that three unknown quantities, i.e. ¹² , ^u and ²² , need to be acquired in order to determine the relationship between r ^B and Γ ^A . Generally, three conditions (equations) are needed to determine three unknown quantities. Herein, the required three conditions can be formed by using three assistant comparison measurements, and

¹² , ^u and ²² can be derived in dependence on formula (12), of which the detailed process is as follows.

Three typical products to be identified (fluorescence lamp) are chosen and used for the above-mentioned three assistant comparison measurements, respectively. The read-out values of the three typical products measured by the detection device 221 and the device 211 are F^ ₁ , r^ ₂ ■ _> r« , as well as F ₅₁ , F ₅₂ , F ₅₃ , respectively. By pairwise introducing the quantities into formula (12), the following formulas can be derived:

1 r _A2 (14)

r _B2 +s^

1

(15)

^■ + S ^D

1 r „3 + + O v ₁ ^D , ς.Z) ς.Z) ς.Z)

The following formulas of ¹² , ^u and ²² can be derived by combining formulas (3) to (15): ς.Z> _ ^± r Al ¹ Γ Bl ¹ Γ- A3 ( V ^± Γ Bl - ^± Γ B3 \ J+^ ^A Γ Al ¹ Γ A2 ¹ Γ Bi (X ¹ ΓBl - ^± Γ Bl \ )+ ^{τ ±} Γ Bl ¹ Γ A2 ¹ Γ Ai ( y ¹ Γ B3 - ^± Γ Bl \ ) (λ fλ

¹ rAl ¹ ΓA3 - ^A ΓBl (X ¹ ΓBl - ^A ΓB3 )J i _sD v _rø

Subsequently, the calibrated relationship between r ^B and r ^A can be determined by introducing the acquired ¹² , ^u and ²² into formula (12). Therefore, according to this embodiment, calibration units for performing the following functions can be mounted to all detection devices other than the device 211, wherein the calibration units are capable of translating the information of an electronic/electric product relating to the radio input impedance acquired by the local detection device into the information of the same electronic/electric product relating to the radio input impedance acquired by the device 211. Thus, numerous detection devices follow the same standard, so that it is avoided that identification results of different detection devices for the same electronic/electric product differ.

According to the above-mentioned preferred embodiment, the real line 52 in Fig.5 illustrates the modulus values of the radio input impedance of the fluorescence lamp 318 in a partial frequency band acquired by the device 211, and the broken line 51 in Fig.5 illustrates the modulus values of the radio input impedance of the fluorescence lamp 318 in the same frequency band acquired by the detection device 221. The calibrated result, for example, the curve 53 marked with dots in Fig.5, can be acquired by introducing the measurement result of the detection device 221 into formula (11). In other words, the curve 53 is acquired by rendering the measurement result of the detection device 221 equivalent to the measurement result of the device 211. Only the relationship of the curves in a partial frequency band is illustrated in Fig.5, and the curve 53 matches the curve 52 in the frequency band (not shown in the Figure).

As illustrated in Fig.5, the curves 53 and 52 are not close enough near the frequency points of 10 ⁹ ~l.l ^χ 10 ⁹ Hz. Therefore, these frequency points can be omitted during determination of genuineness or counterfeit and it is of course accordingly impossible to make use of most of the acquired information relating to the radio input impedance. Therefore, according to a more preferred embodiment of the present invention, formula (11) is determined by using more fluorescence lamps for assistant measurement besides the above-mentioned three typical fluorescence lamps to be identified. In this embodiment, the number of these fluorescence lamps is N. By using the device 211 and the detection device 221, respectively, to measure the information relating to the radio input impedance, the known quantities of and can be obtained, and in this preferred embodiment, it is necessary to determine au au au

¹² ' ²² ' ⁱⁱ based on these known quantities, while formula (11) can be rewritten as an equation set (19):

K ¹ A ) ¹ B ^~ i ^Λ 12 j + ¹ B ^Λ 22 + ^Λ 11 ^Λ 22 ^~ K ¹ A ) ^Λ l l + ^H , i = \ ...N (\ <)) r Γ ¹ Γ ^~ \ ^H wherein, L J denotes the inverse of a matrix, L J denotes the transpose of a matrix, and n ¹ . denotes the measured noise. In order to solve the non-linear equation set (19), the non-linear item S ^u S ²² must first be removed.

Therefore, the following equation set (20) consisting of ^ ^~ ' equations can be obtained, wherein i = h-N ^~ hk = i + l,..,N .

D oD of)

Since the distribution of the noise model, i.e. n ' is useless, S ¹² ' S ²² ' S ^u can be obtained by using the following minimum square estimate method: wherein

fore, a better relationship between r Γ

There ^B and ^ in a broader band, even in a full band, can be obtained, wherein a more accurate calibrated result, such as the curve 54, can be obtained by introducing the measurement result of the detection device 221 into the improved formula (11). As compared with the curve 53, the curve 54 matches the curve 52 better. Thus, there is no need to abandon the measurement data of part of the frequency points as the preceding embodiment does, so that it is possible to take full advantage of the measurement data, and the identification result for the electronic/electric product is more credible. In a practical application, a calibration unit can be mounted in the detection device of the structure as illustrated in Fig.3, between the A/D converter 314 and the decision unit 315. The third unit is used to standardize the measurement data acquired by the detection device 221 as the data acquired by the device 211 in accordance with the relationship between r ^B and Γ ^A determined in formula (11), and to supply it to the decision unit 315 for judgment. In existing electronic locking systems, all electronic keys and electronic locks are provided with circuits inside. When an electronic key tries to open an electronic lock in a contact mode or a contactless mode, the electronic key and the electronic lock will exchange an electric signal so as to achieve authentication.

However, the above-mentioned electronic locking systems have a poor resistance against malicious attack, mainly because an electronic key based on the technique can be easily counterfeited and the result will not be detected by the electronic lock, since a counterfeiter can absolutely make a fake electronic key generating and emitting a signal which is similar enough to, or even the same as, that of an allowable one with existing technologies.

Inherent characteristics of an electronic element, such as impedance, can be used to realize an electronic locking system as well as to determine whether an electronic/electric product is genuine or a counterfeit. Fig.6a illustrates an electronic key according to an embodiment of the present invention, and Fig.6b illustrates an electronic lock according to an embodiment of the present invention.

In this document, the electronic control system and method provided by the present invention will be described, taking the electronic locking system as an example. Reading this specification, those skilled in the art can realize a bank card system, an authorization/admission system of software, and other similar systems based on the present invention, without any creative work, and all of these systems and methods fall within the protective scope defined by the appended claims. As illustrated in Fig.6a, an electronic key 60 which is equivalent to an allowable trigger comprises impedance elements 606, 607 and 608, the impedance element set being composed of the three impedance elements connected to a plurality of contact terminals 601-604 of a trigger portion and being used to electrically contact to the electronic lock which is equivalent to an electronic controller. For convenience of grasping, the electronic key 60 further comprises a handle portion 605 so that it has a shape similar to a conventional metal key.

It will be evident to those skilled in the art that the constructions of the electronic keys of each embodiment of the present invention are not limited to the embodiment illustrated in Fig.6a. There is no limitation of the type of impedance element inside the electronic key of the present invention. When the electronic key comprises more than one impedance element, these impedance elements may be of the same type, such as a resistor, or of different types, such as a resistor, a capacitor, an inductor, or a combination of any two of this resistor, capacitor and inductor. According to different embodiments of the present invention, the number of contact terminals of the key portion (trigger portion) is not limited to four. For example, the number of contact terminals of the key portion may be only two, or more than four. Furthermore, especially for electronic keys with a plurality of impedance elements, the relationship of connection between the impedance element set consisting of the plurality of impedance elements and the plurality of contact terminals of the key portion is not limited to Fig.6a. The relationship of connection only needs to satisfy the condition that the impedance value between at least two contact terminals of the key portion is not equal to zero.

Fig.6b illustrates the electronic lock 61 pairwise used with the electronic key as illustrated in Fig.6a. The electronic lock 61 comprises a plurality of contact terminals 611-614 of a control portion at the position which is electrically contactable to the electronic key, and a detection circuit 615 which is coupled to the plurality of contact terminals 611-614 and is capable of measuring the corresponding impedance via at least two contact terminals of the lock portion (control portion) when an electronic key is effectively electrically contacted to the electronic lock 61. For example, when the effective electrical contact between the contact terminals of the key portion of the electronic key 60 as illustrated in Fig.6a and the corresponding contact terminals of the lock portion of the electronic lock 61 is realized in a non- limiting inserting mode, the detection circuit 615 can measure the impedance between the contact terminals 611 and 613 of the control portion, i.e. the impedance of the impedance element 606, and it can also measure the total impedance of the series-wound circuit of the impedance elements 606, 607 and 608 via the contact terminals 611 and 612 of the control portion. Other impedances can be measured in similar ways. The detection circuit 615 herein realizes the function of an impedance detector.

The impedance values of each allowable switch key corresponding to the electronic lock are stored in a small storage unit (not shown), which is in contact with and accessible by the detection circuit 615, or in the detection circuit 615 itself. These impedance values are taken as allowable switch impedances, namely allowable triggering impedances. These prestored allowable switch impedances can be stored in a way which can be matched with the corresponding contact terminal pair of the control portion.

For example, the impedance elements are simple resistors. Since nowadays widely used detection devices may have a precision of 0.1 Ω , e.g. 611-613- 1000.1Ω indicates that the measured impedance between contact terminals 611 and 613 of the lock portion must belOOO.lΩ . Otherwise, the electronic key will not be regarded as an allowable switch key. Of course, the electronic lock 61 stores a plurality of items of information similar to 611-613- 1000.1Ω . The opening/closing operation of the electronic/mechanical switch of the electronic lock will thus be successfully triggered only when each impedance value of an electronic key measured by the detection circuit 615 via each pair of contact terminals of the lock portion matches corresponding prestored information.

The situation described in the preceding embodiment is more applicable to the situation in which the prestored allowable switch impedance and the impedance measured by the detection circuit 615 have equivalent precision values. When the two precision values differ, for example, the prestored allowable switch impedance is accurate to one decimal place, whereas the detection circuit is accurate to two decimal places, a reasonable threshold of more than zero can be defined only when the absolute value of the difference between the measured impedance and the corresponding allowable switch impedance is less than or equal to the threshold. Only then will it be affirmed that the measured impedance is equivalent to the allowable switch impedance.

The detection circuit 615 mainly implements the functions of an impedance detector and a processor. Of course, the detection circuit 615 may be replaced by an impedance detector and a processor which are independent of each other and, in some other embodiments, are coupled to each other.

In order to measure the impedance, a power supply 616 such as a dry battery is required.

Furthermore, the electronic lock also comprises an electronic/mechanical switch 617, which is accordingly the module for performing authorization or admission of bank cards or software, and is responsible for performing the opening and closing operation in accordance with the result obtained by the detection circuit 615. For example, when the electronic lock 61 is closed, the detection circuit 615 detects the information of insertion of an allowable switch key, and then the electronic-mechanical switch 617 performs an opening operation, or, in the opposite case, a closing operation.

Sometimes there is a plurality of allowable switch keys which corresponds to an electronic lock 61, but it is difficult to avoid loss of an allowable switch key. Therefore, alternatively, the electronic locking system provided by the present invention further comprises at least one defining key, namely a definition trigger, which will be described below.

The owner of an allowable switch key, such as the owner of a house, realizes effectual electrical contact between the contact terminals of the trigger portion of the defining key and corresponding contact terminals of the control portion of the electronic lock, and the detection circuit 615 will identify it as a defining key, whereafter the procedure of defining a new allowable switch key is triggered. For example, in a subsequent period of time, such as 20s after the defining procedure has been triggered, the owner withdraws the defining key and uses other electronic keys to realize effectual electrical contact with the electronic lock, and then the impedances of these other electronic keys will be recorded as allowable switch impedances. After the defining procedure has been finished, these other electric keys may be used as pre-existent electronic keys to open the electronic lock. Of course, if a pre-existent electronic key is lost, its impedance should preferably be deleted from prestored allowable switch impedances. For this purpose, the electronic lock 61 further comprises a user interface (not shown in the Figures) which enables a user to choose, through one or more exchange modes, whether to delete one or more pre-existent allowable switch impedances. Furthermore, the procedure of defining a new allowable switch impedance can be accomplished by means of user input, which may be keystroke input, voice input, and the like. When voice input is used, the electronic lock needs to perform further identification of the voice signal and store the identified impedance as the new allowable switch impedance.

An allowable switch key may be a defining key as well. According to an embodiment of the present invention, the contacting time will be recorded when the detection circuit 615 detects effectual electrical contact between an allowable switch key and the electronic lock 61. If the contacting time is beyond a predefined value, for example, 5 seconds, the decision is made that the condition of defining a new allowable switch key is satisfied, and then a defining procedure similar to that described above will be triggered.

Since existing impedance measuring techniques are satisfactory enough, and at least one in a thousand errors occur in the manufacture of impedance elements, for example, resistors, the electronic locking systems provided in each embodiment of the present invention are very resistant to malicious attacks. For example, for a plurality of resistors with a nominal value of 1MΩ , their real impedance will be in the range of 1MΩ ± IkD. . The impedance measuring technique with a precision of 0.1 Ω can realize the identification ratio of at least 10 ⁴ for resistors having a value of 1MΩ . In other words, the probability is only one in ten thousand that an allowable switch key is successfully copied so as to open the electronic lock 61 and make a malicious attack. If the impedance element set has a more complicated construction, the success ratio of such malicious attacks will decline exponentially.

Impedances of electronic elements may be influenced by environmental factors, such as temperature. Therefore, the plurality of allowable switch impedances prestored in the electronic lock 61 preferably corresponds to a predefined temperature of, for example, 25°C. Thus, when the current environment temperature deviates from the predefined temperature, it is necessary to standardize the measured impedance with respect to the impedance below the defined temperature, or to determine a new allowable switch impedance below the current environment temperature in accordance with prestored allowable switch impedances so as to compare the two sets of values which can be matched with each other and determine whether the electronic key is an allowable switch key. The electronic lock 61 preferably comprises a temperature monitor (not shown in the Figure), which is used for monitoring the environment temperature and informing it to the detection circuit 615. The detection circuit 615 performs the above-mentioned standardization operation on the basis of known features of impedance elements varying with temperature, and performs a comparison based on the equivalent result.

The processor is further used for determining the equivalent impedance of the measured impedance of the electronic key below said predefined temperature based on current temperature information acquired by the temperature monitor, subsequently for comparing said equivalent impedance with at least one prestored allowable switch impedance, and for controlling the electronic lock to open or close when the differential between said equivalent impedance and any of the prestored allowable switch impedances is below said predefined threshold.

It will be evident to those skilled in the art that it is only for the sake of convenience that the electronic key which is illustrated in Fig.6a and Fig.6b is similar to a conventional metal key. Actually, any electronic key according to the present invention may have various constructions for the purpose of cooperation with the electronic keys, while the electronic locks may also have various constructions. All of these variations fall within the protective scope of the appended claims. Some embodiments of the present invention have been described hereinbefore. It is to be noted that the present invention is not limited to these special embodiments and that those skilled in the art are able to conceive many variations and modifications without departing from the scope of the appended claims.