Abstract:
A working method of an NFC token. The method comprises: a micro control unit in a token performing system initialization; resetting a near field communication chip in the token and sending a near field communication chip setting instruction to the near field communication chip; waiting to receive a near field communication chip setting instruction return value; upon receiving the near field communication chip setting instruction return value, sending a first preset instruction to the near field communication chip; waiting to receive a first preset instruction return value; and upon receiving the first preset instruction return value, sending a second preset instruction comprising a dynamic password to the near field communication chip. The present invention has the beneficial effects that: the token is well compatible with a mobile platform, and is convenient to use, thereby simplifying the operation procedure of a user.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to information security field, more particularly relates to a working method for NFC token. 
       PRIOR ART 
       [0002]    Due to rapid development of smart terminals such as smart phone, etc. in information security field, mobile bank, as a new service combining currency electronization and mobile communication, makes people deal with many financial businesses at any time and any places. In order to assure security of mobile bank business, respective banks begin to apply devices, such as challenge-response token, earphone key, etc., in mobile banks. However, the earphone key has bad compatibility. Though the challenge-answer token has no problem of compatibility, the challenge-response token is not convenient for using because it requires more artificial intervention. 
         [0003]    Near Field Communication (NFC), called near distance wireless communication, is a high frequency wireless communication technology with short distance, which allows data transmission between electronic devices in form of contactless point to point. Compared with other wireless communication technology, NFC has better security. Therefore, NFC is regarded as having better application prospect in fields such as mobile phone payment, etc. 
       SUMMARY OF THE INVENTION 
       [0004]    The object of the present invention is to provide a working method for NFC token, which has a better compatibility for mobile platform, is convenient for using, and simplifies operating procedure of a user. 
         [0005]    Therefore, the present invention provides a working method for an NFC token, which has implementing procedure as follows. 
         [0006]    Step  1 ) performing, by a micro control unit of the token, system initializing; 
         [0007]    Step  2 ) resetting, by the micro control unit, a near field communication chip of the token; 
         [0008]    Step  3 ) sending, by the micro control unit, a setting near field communication chip instruction to the near field communication chip; 
         [0009]    Step  4 ) waiting, by the micro control unit, for a return value of the setting near field communication chip instruction returned from the near field communication chip; 
         [0010]    Step  5 ) sending, by the micro control unit, a first preset instruction to the near field communication chip when the micro control unit reads the return value of the setting near field communication chip instruction returned from the near field communication chip; 
         [0011]    Step  6 ) waiting, by the micro control unit, for a return value of the first preset instruction returned from the near field communication chip; and 
         [0012]    Step  7 ) sending, by the micro control unit, a second preset instruction containing a dynamic password generated by the token when the micro control unit reads the first preset instruction value returned from the near field communication chip; 
         [0013]    before sending a second preset instruction containing a dynamic password generated by the token, the method further comprising computing and generating, by the micro control unit, the dynamic password. 
         [0014]    Preferably, Step S 2  further comprises: 
         [0015]    Step S 2 ′) waiting, by the micro control unit, for confirming start information input by a user; performing Step S 3  when the confirming start information input by the user is received; otherwise, keeping on waiting for the confirming start information input by the user; 
         [0016]    in this case, Step S 2 ′ specifically comprises: checking, by the micro control unit, level of a key interrupting pin; when the level of the key interrupting pin is high level, representing that the confirming start information input by a user is received and performing Step S 3 ; when the level of the key interrupting pin is low level, representing that the confirming start information input by a user is not received and keeping on checking the level of the key interrupting pin; further, before sending, by the micro control unit, the first preset instruction to the near field communication chip and/or before sending, by the micro control unit, the second preset instruction containing the dynamic password generated by the token to the near field communication chip, the method further comprises: checking the level of the key interrupting pin; keeping on performing procedure if the level is high level, going back to Step S 2  if the level is low level, or 
         [0017]    Step S 2 ′ specifically comprises: starting, by the micro control unit, key interrupting, checking a start flag, performing Step S 3  in the case that the start flag is set, which represents that the confirming start information input by the user is received; keeping on checking the start flag in the case that the start flag is not set, which represents that the confirming start information input by the user is not received; correspondingly, Step S 1  further comprises initializing, by the micro control unit, key interrupting, checking whether the start flag is set when the micro control unit receives the key interrupting; if yes, exit the key interrupting, otherwise, setting the start flag and exit the key interrupting; or 
         [0018]    Step S 2 ′ specifically comprises: starting, by the micro control unit, key interrupting, checking the start flag, performing Step S 3  in the case that the start flag is set which represents that the confirming start information input by the user is received; keeping on checking the start flag in the case that the start flag is not set which represents that the confirming start information input by the user is not received; correspondingly, Step S 1  further comprises: initializing, by the micro control unit, key interrupting and setting the key interrupting as rising edge triggering; checking whether the start flag is set when the micro control unit receives the key interrupting, if yes, exiting key interrupting, otherwise setting the start flag and setting key interrupting as falling edge triggering, exiting key interrupting. 
         [0019]    Preferably, Step S 3  further comprises: setting, by the micro control unit, timeout limit of the near field communication chip; 
         [0020]    in this case, setting, by the micro control unit, timeout limit of the near field communication chip specifically comprises: sending a setting timeout limit instruction to the near field communication chip, the setting timeout limit instruction contains power on response timeout limit and communication timeout limit. 
         [0021]    Preferably, Step S 3  specifically comprises: setting, by the micro control unit, a sequence number of the token, generating a configuring target device instruction upon the sequence number of the token, sending the configuring target device instruction to the near field communication chip; correspondingly, the first preset instruction is a receiving data instruction, the second preset instruction is a sending data instruction. 
         [0022]    Preferably, Step S 3  specifically comprises: setting, by the micro control unit, simulation card parameters, generating a configuring target device instruction upon the simulation card parameters, sending the configuring target device instruction to the near field communication chip, the simulation card parameters comprises simulation card type and simulation card ID; correspondingly, reading, by the micro control unit, the return value of the setting near field communication chip instruction returned from the near field communication chip, before sending the first preset instruction to the near field communication chip, the method further comprises: sending, by the micro control unit, the second preset instruction to the near field communication chip, when the micro control unit reads a second preset instruction return value returned from the near field communication chip, sending the first preset instruction to the near field communication chip; the first preset instruction is a obtaining data instruction, the second preset instruction is a sending data instruction. 
         [0023]    Preferably, Step S 3  specifically comprises: setting, by the micro control unit, card searching type and card searching rate; generating a configuring initiator instruction upon the card searching type and card searching rate, sending the configuring initiator instruction to the near field communication chip; correspondingly, the first preset instruction and the second preset instruction are both data exchanging instruction. 
         [0024]    Step S 4  to Step S 7  specifically comprises: 
         [0025]    Step A 1 ) waiting, by the micro control unit, for receiving data interrupt, performing Step A 2  when the micro control unit receives data interrupting; 
         [0026]    Step A 2 ) reading, by the micro control unit, return data of the near field communication chip, checking read data, sending the first preset instruction to the near field communication chip if the read data is the setting near field communication chip instruction and go back to Step A 1 ; sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip if the read data is the return value of the first preset instruction. 
         [0027]    Correspondingly, Step S 1  further comprises: initializing data interrupting; 
         [0028]    preferably, Step S 4  to S 7  specifically comprises: 
         [0029]    Step B 1 ) checking, by the micro control unit, trigger flag, if the trigger flag is not set, waiting for data interrupting and going back to Step B 1 ; if the trigger flag is set, performing Step B 2 ; 
         [0030]    when the micro control unit receives data interrupting, reading return data of the near field communication chip, checking the read data, if the read data is the return value of the near field communication chip, updating the work state of the token as a first preset state and setting the trigger flag; if the read data is the return value of the first preset instruction, updating the work state of the token to be a second preset state and setting the trigger flag; 
         [0031]    Step B 2 ) resetting, by the micro control unit, the trigger flag, checking the work state of the token, sending the first preset instruction to the near field communication chip if the work state is the first preset state and going back to Step B 1 ; sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip if the work state is the second preset state. 
         [0032]    Correspondingly, Step S 1  further comprises: initializing the data interrupt; Step S 2  further comprises: initializing the work state of the token to be initial state. 
         [0033]    Preferably, Step S 4  to S 7  specifically comprises: 
         [0034]    Step C 1 ) inquiring, by the micro control unit, level of the data interrupting pin, performing Step C 2  if the level of the data interrupting pin is high level; 
         [0035]    Step C 2 ) reading, by the micro control unit, the return data of the near field communication chip, checking the read data, sending the first preset instruction to the near field communication chip if the read data is the return value of the near field communication chip instruction and going back to Step C 1 ; sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip if the read data is the return value of the first preset instruction; 
         [0036]    Correspondingly, Step S 1  further comprises: initializing data interrupting. 
         [0037]    Preferably, before computing and generating the dynamic password, the method further comprises: prompting, by the micro control unit, the user to input confirming generating password information, determining whether the confirming generating password information input by the user is received in a first preset time, if yes, generating the dynamic password; otherwise, going back to Step S 2 , 
         [0038]    in this case, determining whether the confirming generating password information input by the user is received in the first preset time specifically comprises: checking, by the micro control unit, the level of the key interrupt pin, determining whether the level of the interrupt pin changes to be high level in the first preset time, if yes, the confirming generating password information input by the user is received in the first preset time; otherwise, the confirming generating password information input by the user is not received in the first preset time; or, 
         [0039]    determining whether the confirming generating password information input by the user is received in the first preset time specifically comprises: waiting, by the micro control unit, for receiving key interrupting and determining whether the key interrupting is received in the first preset time, if yes, the confirming generating password information input by the user is received in the first preset time; otherwise, the confirming generating dynamic password information input by the user is not received in the first preset time; correspondingly, Step S 1  further comprises initializing key interrupting. 
         [0040]    Preferably, in the case that the micro control unit reads the return value of the first preset instruction returned from the near field communication chip, before sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip, the method further comprises: prompting, by the micro control unit, the user to input confirming sending password information and determining whether the confirming sending password information input by the user is received in a second preset time, if yes, sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip; otherwise, going back to Step S 2 ; 
         [0041]    in this case, determining whether the confirming sending password information input by the user is received in a second preset time specifically comprises: checking, by the micro control unit, the level of the key interrupting pin, determining whether the level of the interrupt pin changes to be high level in the second preset time, if yes, the confirming generating dynamic password information input by the user is received in the second preset time; otherwise, the confirming generating dynamic password information input by the user is not received in the second preset time; or, 
         [0042]    determining whether the confirming sending password information input by the user is received in a second preset time specifically comprises: waiting, by the micro control unit, for receiving key interrupting and determining whether the key interrupting is received in the second preset time, if yes, the confirming sending dynamic password information input by the user is received in the second preset time; otherwise, the confirming sending dynamic password information input by the user is not received in the second preset time; correspondingly, Step S 1  further comprises initializing key interrupting. 
         [0043]    Preferably, computing and generating the dynamic password specifically comprises: computing and generating the dynamic password upon a preset key and an event factor; or 
         [0044]    computing and generating the dynamic password specifically comprises: computing and generating the dynamic password upon the challenge value, the preset key and the event factor; correspondingly, before computing and generating the dynamic password, the method further comprises: obtaining the challenge value from the return value of the first preset instruction returned from the near field communication chip and displaying the challenge value; or 
         [0045]    computing and generating the dynamic password specifically comprises: computing and generating the dynamic password upon the challenge value, the preset key, the event factor and the time factor; correspondingly, before computing and generating the dynamic password, the method further comprises: obtaining the challenge value from the return value of the first preset instruction returned from the near field communication chip and displaying the challenge value; or 
         [0046]    computing and generating the dynamic password specifically comprises: generating the dynamic password upon the preset key and the time factor; or 
         [0047]    computing and generating the dynamic password specifically comprises: obtaining the challenge value from the return value of the first preset instruction returned from the near field communication chip and displaying the challenge value. 
         [0048]    Preferably, after Step S 7  the method further comprises: waiting, by the micro control unit, for the return value of the second preset instruction returned from the near field communication chip, sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip when the micro control unit reads the return value of the second preset instruction returned from the near field communication chip; 
         [0049]    when the micro control unit reads the return value of the first preset instruction returned from the near field communication chip, before sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip, the method further comprises: checking the state parameter in the return value of the first preset instruction, if the state parameter is a preset value, going back to Step S 2 ; if the state parameter is not the preset value, sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip; 
         [0050]    when the micro control unit reads the return value of the second preset instruction returned from the near field communication chip, before sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip, the method further comprises: checking the state parameter in the return value of the second preset instruction, if the state parameter is a preset value, going back to Step S 2 ; if the state parameter is not the preset value, sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip. 
         [0051]    The advantages of the present invention includes that the token has good compatibility for mobile platform and manual operation of the user is reduced when the token is used, which simplifies operating procedure of a user. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0052]      FIG. 1  is a flow diagram of a working method for an NFC token of Embodiment 1 of the present invention; 
           [0053]      FIG. 2  is a flow diagram of a working method for an NFC token of Embodiment 2 of the present invention; 
           [0054]      FIG. 3  is a flow diagram of a working method for an NFC token of Embodiment 3 of the present invention; 
           [0055]      FIG. 4  is a flow diagram of a working method for an NFC token of Embodiment 4 of the present invention; 
           [0056]      FIG. 5  is a flow diagram of a working method for an NFC token of Embodiment 5 of the present invention; 
           [0057]      FIG. 6  is a flow diagram of a working method for an NFC token of Embodiment 6 of the present invention; 
           [0058]      FIG. 7  is a flow diagram of a working method for an NFC token of Embodiment 7 of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0059]    The technical solutions of the embodiments of the disclosure are described clearly and completely in conjunction with the accompanying drawings as follows. Apparently, the described embodiments are merely a part of but not all of the embodiments according to the disclosure. Based on the described embodiments of the disclosure, other embodiments obtained by those skilled in the art without any creative work belong to the scope of the disclosure. 
         [0060]    The NFC token provided by the present invention is a device supporting NFC, which can exchange data with other devices supporting NFC in active mode or passive mode. 
       Embodiment 1 
       [0061]    Embodiment 1 of the present invention provides a working method for an NFC token, the token comprises a Micro Control Unit (MCU) and Near Field Communication (NFC) chip. Referring to  FIG. 1 , the working method of the token specifically comprises: 
         [0062]    Step S 1 , the MCU in the token performs system initializing; 
         [0063]    Step S 2 , the MCU resets the NFC chip in the token; 
         [0064]    Step S 3 , the MCU sends a setting NFC chip instruction to the NFC chip; 
         [0065]    in Embodiment 1, Step S 3  further comprises Step S 3 ′) setting a timeout limit of the NFC chip by the MCU; 
         [0066]    Step S 3 ′ specifically comprises: the MCU sends a setting timeout limit instruction to the NFC chip; the setting timeout limit instruction contains a power up response timeout limit and communication timeout limit. 
         [0067]    Step S 4 , the MCU waits for a return value of the setting NFC chip instruction returned from the NFC chip; 
         [0068]    Step S 5 , a first preset instruction is sent to the NFC chip when the MCU reads the return value of the setting NFC chip instruction returned from the NFC chip; 
         [0069]    Step S 6 , the MCU waits for a return value of the first preset instruction returned from the NFC chip; 
         [0070]    Step S 7 , a second preset instruction containing a dynamic password generated by the token is sent to the NFC chip, when the MCU reads the return value of the first preset instruction returned from the NFC chip; 
         [0071]    in Embodiment 1, before sending a second preset instruction containing a dynamic password generated by the token to the NFC chip when the MCU reads the return value of the first preset instruction returned from the NFC chip, the method further comprises: checking a state parameter in the return value of the first preset instruction, going back to Step S 2  if the state parameter is a preset value; sending the second preset instruction containing the dynamic password generated by the token to the NFC chip if the state parameter is not the preset value; 
         [0072]    before sending the second preset instruction containing the dynamic password generated by the token to the NFC chip, the method further includes computing and generating the dynamic password by the MCU. 
         [0073]    In Embodiment 1, Step S 2  further includes Step S 2 ′) waiting, by the MCU, for confirming start information input by a user, going to Step S 3  when the confirming start information input by the user is received; otherwise, keeping on waiting for the user to input the confirming start information; 
         [0074]    Step S 2 ′ specifically includes checking, by the MCU, level of a key interrupting pin, executing Step S 3  when the level of the key interrupting pin is high level, which represents that the confirming start information input by the user is received; keeping on checking the level of the key interrupting pin when the level of the key interrupting pin is low level, which represents that the confirming start information input by the user is not received; 
         [0075]    correspondingly, before sending, by the MCU, the first preset instruction to the NFC chip and/or sending, by the MCU, the second preset instruction containing the dynamic password generated by the token to the NFC chip, the method further includes checking the level of the key interrupting pin, keeping on executing if the level is high level; going back to Step S 2  if the level is low level; or 
         [0076]    Step S 2 ′ specifically includes: starting, by the MCU, key interrupting and checking a start flag; executing Step S 3  when the start flag is set, which represents that the confirming start information input by the user is received; keeping on checking the start flag when the start flag is not set, which represents that the confirming start information input by the user is not received; 
         [0077]    correspondingly, Step S 1  further includes initializing key interrupting by the MCU; checking whether the start flag is set when the MCU receives the key interrupting; if yes, exiting the key interrupting; otherwise, setting the start flag and exiting the key interrupting; or 
         [0078]    Step S 2 ′ specifically includes: initializing key interrupting by the MCU; checking the start flag, executing Step S 3  when the start flag is set, which represents that the confirming start information input by the user is received; keeping on checking the start flag when the start flag is not set, which represents that the confirming start information input by the user is not received; 
         [0079]    correspondingly, Step S 1  further includes initializing key interrupting by the MCU; and setting the key interrupting as rising edge triggering; checking whether the start flag is set when the MCU receives the key interrupting, if yes, exiting key interrupting, otherwise setting the start flag and setting key interrupting as falling edge triggering, exiting key interrupting. 
         [0080]    In Embodiment 1, before computing and generating the dynamic password, the method further includes: 
         [0081]    Step  30 ) the MCU prompts the user to input confirming generating password information; 
         [0082]    Step  40 ) the MCU determines whether the confirming generating password information input by the user is received in a first preset time, if yes, computing and generating the dynamic password; otherwise, going back to Step S 2 . 
         [0083]    Step  40  specifically includes checking, by the MCU, level of the key interrupting pin, determining whether the level of the interrupt pin changes to be high level in the first preset time, if yes, the confirming generating password information input by the user is received in the first preset time; otherwise, the confirming generating password information input by the user is not received in the first preset time; or 
         [0084]    Step  40  specifically includes waiting, by the MCU, for receiving key interrupting and determining whether the key interrupting is received in the first preset time, if yes, the confirming generating password information input by the user is received in the first preset time; otherwise, the confirming generating dynamic password information input by the user is not received in the first preset time; 
         [0085]    correspondingly, Step S 1  further comprises initializing key interrupting. 
         [0086]    In Embodiment 1, when the MCU reads the return value of the first preset instruction returned from the near field communication chip, before sending the second preset instruction containing the dynamic password generated by the token to the near field communication chip, the method further comprises: 
         [0087]    Step  50 ) prompting, by the MCU, the user to input confirming sending password information; 
         [0088]    Step  60 ) determining, by the MCU, whether the confirming sending password information input by the user is received in a second preset time, if yes, sending the second preset instruction containing the dynamic password generated by the token to the NFC chip; otherwise, going back to Step S 2 ; 
         [0089]    Step  60  specifically includes: checking, by the MCU, the level of the key interrupting pin, determining whether the level of the interrupt pin changes to be high level in the second preset time, if yes, the confirming generating dynamic password information input by the user is received in the second preset time; otherwise, the confirming generating dynamic password information input by the user is not received in the second preset time; or 
         [0090]    Step  60  specifically includes: waiting, by the MCU, for receiving key interrupting and determining whether the key interrupting is received in the second preset time, if yes, the confirming sending password information input by the user is received in the second preset time; otherwise, the confirming generating dynamic password information input by the user is not received in the second preset time; 
         [0091]    correspondingly, Step S 1  further comprises initializing key interrupting. 
         [0092]    In Embodiment 1, after Step S 7 , the method further includes: waiting, by the MCU, for the return value of the second preset instruction returned from the NFC chip, sending the second preset instruction containing the dynamic password generated by the token to the NFC chip when the MCU reads the return value of the second preset instruction returned from the NFC chip; 
         [0093]    Further, when the MCU reads the return value of the second preset instruction returned from the NFC chip, before sending the second preset instruction containing the dynamic password generated by the token to the NFC chip, the method further comprises: checking the state parameter in the return value of the second preset instruction, if the state parameter is a preset value, going back to Step S 2 ; if the state parameter is not the preset value, sending the second preset instruction containing the dynamic password generated by the token to the NFC chip. 
       Embodiment 2 
       [0094]    Embodiment 2 of the present invention provides a working method for an NFC token. The token includes an MCU and an NFC chip. The token as a target device communicates with an initiator. Referring to  FIG. 2 , the working method for the token specifically includes that the MCU of the token performs following steps: 
         [0095]    Step  101 , system initializing is performed; 
         [0096]    Step  102 , the NFC chip is reset; 
         [0097]    Specifically, in Embodiment 2, resetting the NFC chip includes controlling its MCU_SPI_RST pin to output low level; after delaying a preset time, controlling its MCU_SPI_RST pin to output high level; 
         [0098]    preferably, in Embodiment 2, before Step  102 , the method can include: checking battery power and prompting that battery power is two low when the battery power is lower than preset battery power; specifically, that battery power is too low is prompted by displaying on a screen and/or changing color of an indicator lamp and/or buzzing and/or voice. 
         [0099]    Step  103 , a timeout limit of the NFC chip is set; 
         [0100]    Specifically, in Embodiment 2, setting the timeout limit of the NFC chip includes: the MCU sends a setting timeout limit instruction to the NFC chip; the timeout limit instruction includes power up response timeout limit and communication timeout limit; 
         [0101]    Preferably, in Embodiment 2, setting timeout limit instruction is RFConfiguration instruction with Cfqlten parameter of 0x02. 
         [0102]    Step  104 , whether a setting timeout limit response returned from the NFC chip is received in a preset time is determined, if yes, keep on execute Step  105 ; otherwise, communication is failed and go back to Step  102 ; 
         [0103]    Step  105 , whether setting timeout limit of the NFC chip is successful is determined upon the received setting timeout limit response, if yes, execute Step  106 ; otherwise, communication is failed and go back to Step  102 ; 
         [0104]    Specifically, in Embodiment 2, determining whether setting timeout limit of the NFC chip is successful upon the received setting timeout limit response includes: determining whether the data on preset bytes of the received setting timeout limit response, if yes, setting the timeout limit of the NFC chip is successful; otherwise, setting the timeout limit of the NFC chip is failed; 
         [0105]    Preferably, in Embodiment 2, whether the data on the first three bytes of the received setting timeout limit response is 0x 00 00 FF is determined. 
         [0106]    Step  106 , the NFC chip is set as target status of active mode; a sequence number of the token is set and sent to the NFC chip; 
         [0107]    Specifically, in Embodiment 2, Step  106  includes: setting the sequence number of the token, generating a configuring target device instruction upon the set sequence number of the token and sending the generated configuring target device instruction to the NFC chip; 
         [0108]    Preferably, in Embodiment 2, the sequence number of the token is a data with 10 bytes; the configuring target device instruction is TgInitAsTarget instruction with mode parameter of 0x02. 
         [0109]    Step  107 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, keep on executing Step  108 ; otherwise, communication is failed and go back to Step  102 ; 
         [0110]    Step  108 , whether data returned from the NFC chip exists is determined, if yes, execute Step  109 ; otherwise, go back to Step  108 ; 
         [0111]    In Embodiment 2, Step  108  specifically includes: waiting for data interrupting; when data interrupting is received, execute Step  109 ; otherwise, keep on waiting for data interrupting; or 
         [0112]    In Embodiment 2, Step  108  specifically includes inquiring the level of the data interrupting pin; when the level of the data interrupting pin is high level, execute Step  109 ; otherwise, keeping on checking the level of the data interrupting pin. 
         [0113]    Step  109 , return data of the NFC chip is read and the read data is checked; if the data is a return value of setting NFC chip working mode, state and token parameter, execute Step  110 ; if the data is a return value of obtaining data requirement, execute Step  113 ; 
         [0114]    In Embodiment 2, the return value of setting NFC chip working mode, state and token parameter specifically is configuring target device instruction response; the return value of obtaining data requirement specifically is receiving data instruction response; 
         [0115]    Preferably, in Embodiment 2, the configuring target device instruction is TgInitAsTarget instruction with Mode parameter of 0x02; the receiving data instruction is TgGetData instruction. 
         [0116]    Step  110 , whether the state parameter in the return value of setting NFC chip working mode, state and token parameter is a preset value is checked; if yes, a communication terminal is removed, communication is ended and go back to Step  102 ; otherwise, execute Step  111 ; 
         [0117]    In Embodiment 2, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0118]    Step  111 , the obtaining data requirement is sent to the NFC chip; 
         [0119]    In Embodiment 2, Step  111  specifically includes generating and sending a receiving data instruction to the NFC chip; 
         [0120]    Preferably, in Embodiment 2, the receiving data instruction is TgGetData instruction. 
         [0121]    Step  112 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  108 ; otherwise, communication is failed and go back to Step  102 ; 
         [0122]    Step  113 , whether a state parameter in the return value of the obtaining data requirement is a preset value is checked, if yes, the communication terminal is removed and communication is ended, go back to Step  102 ; otherwise, go to Step  114 ; 
         [0123]    In Embodiment 2, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0124]    Step  114 , a dynamic password is sent to the NFC chip; 
         [0125]    In Embodiment 2, Step  114  specifically includes: generating and sending a sending data instruction containing the dynamic password to the NFC chip; 
         [0126]    Preferably, in Embodiment 2, the sending data instruction is TgSetData instruction. 
         [0127]    In Embodiment 2, before Step  114 , the method further includes computing and generating the dynamic password; 
         [0128]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon a key and an event factor which are preset in the token, and updating the event factor; or 
         [0129]    computing and generating the dynamic password specifically includes updating the event factor preset in the token and computing and generating the dynamic password upon the key and the event factor which are preset in the token; 
         [0130]    further, in Embodiment 2, when the MCU reads the return value of the obtaining data requirement returned from the NFC chip, the method further includes obtaining the challenge value from the return value of the obtaining data requirement and displaying the challenge value; 
         [0131]    correspondingly, computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and event factor which are preset in the token, updating the event factor; or 
         [0132]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the challenge value, and the key preset and the event factor which are preset in the token. 
         [0133]    Further, in Embodiment 2, Step  101  further includes: starting timer interrupting and setting interrupting priority of the timer interrupting to be highest; 
         [0134]    correspondingly, in Embodiment 2, when the MCU receives the timer interrupting, a timer factor preset in the token is updated; 
         [0135]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the time factor which are preset in the token; or, 
         [0136]    computing and generating the dynamic password includes: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor which are preset in the token; or 
         [0137]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the event factor and the time factor which are preset in the token, and updating the event factor; or 
         [0138]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key and the time factor and the event factor which are preset in the token. 
         [0139]    In Embodiment 2, before computing and generating the dynamic password, the method further includes: prompting the user to input confirming generating password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time; if yes, computing and generating the dynamic password; otherwise, go back to Step  102 ; or the method includes: prompting the user to input the confirming generating password information, waiting for receiving the key interrupting and determining whether the key interrupting is received in a preset time, if yes, computing and generating the dynamic password; otherwise, go back to Step  102 . 
         [0140]    In Embodiment 2, before Step  114 , the method further includes: prompting the user to input the confirming sending password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, go to Step  114 ; otherwise, go back to Step  102 ; or the method includes: prompting the user to input the confirming sending password information, waiting for receiving the key interrupting and determining whether the key interrupting is received in the preset time, if yes, go to Step  114 ; otherwise, go back to Step  102 . 
         [0141]    Step  115 , whether the confirming character returned from the NFC chip is received in a preset time is determined, if yes, communication is successful, go back to Step  102 ; otherwise, communication is failed, go back to Step  102 . 
         [0142]    Further, in Embodiment 2, Step  109  further includes: if the read data is the return value of the sending dynamic password, checking whether the state parameter in the return value of the sending dynamic password is the preset value, if yes, the communication terminal is removed and communication is ended, go back to Step  102 ; otherwise, go to Step  114 ; in Embodiment 2, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0143]    Correspondingly, Step  115  is replaced with determining whether the confirming character returned from the NFC chip is received in the preset time, if yes, go back to Step  108 ; otherwise, communication is failed, go back to Step  102 . 
       Embodiment 3 
       [0144]    Embodiment 3 provides a working method for an NFC token, which is as a target device and communicates with an initiator in active mode. Referring to  FIG. 3 , the working method of the token specifically includes following step s performed by an MCU of the token. 
         [0145]    Step  201 , system initializing is performed; 
         [0146]    Step  202 , the NFC chip is reset, the work state of the token is set as initial state and a trigger flag is reset; 
         [0147]    Specifically, in Embodiment 3, resetting the NFC chip includes that the MCU controls its MCU_SPI_RST pin to output low level, delays for a preset time and controls its MCU_SPI_RST pin to output high level; 
         [0148]    Preferably, in Embodiment 3, before Step  202  the method further includes checking battery power, and prompting that battery power is too low when the battery power is lower than a preset battery power; specifically, that battery power is too low is prompted by displaying on a screen and/or changing color of an indicator lamp and/or buzzing and/or voice. 
         [0149]    Step  203 , timeout limit of the NFC chip is set; 
         [0150]    Specifically, in Embodiment 3, setting the timeout time of the NFC chip includes that the MCU sends a setting timeout limit instruction to the NFC chip; the timeout limit instruction includes power up response timeout time and communication timeout time; 
         [0151]    Preferably, in Embodiment 3, setting timeout limit instruction is RFConfiguration instruction with Cfqlten parameter of 0x02. 
         [0152]    Step  204 , whether a setting timeout limit response returned from the NFC chip is received in a preset time is determined, if yes, go to Step  205 ; otherwise, communication is failed and go back to Step  202 ; 
         [0153]    Step  205 , whether setting timeout limit of NFC chip is successful is determined upon the received setting timeout limit response, if yes, go to Step  206 ; otherwise, communication is failed, go back to Step  202 ; 
         [0154]    Specifically, in Embodiment 3, whether setting timeout limit of NFC chip is successful is determined upon the received setting timeout limit response includes: determining whether data on preset bytes of the received setting timeout limit response is a preset character string, if yes, setting the timeout limit of NFC chip is successful; otherwise, setting timeout limit of NFC chip is failed; 
         [0155]    Preferably, in Embodiment 3, whether the data on the first three bytes of the received setting timeout limit response is 0x 00 00 FF is determined. 
         [0156]    Step  206 , the NFC is set as target state in active mode, a sequence number of the token is set and sent to the NFC chip; 
         [0157]    Specifically, in Embodiment 3, Step  206  includes setting the sequence number of the token, generating a configuring target device instruction upon the set sequence number of the token and sending the configuring target device to the NFC chip; 
         [0158]    Preferably, in Embodiment 3, the sequence number of the token is data of 10 bytes; the configuring target device instruction is TgInitAsTarget instruction with Mode parameter of 0x02. 
         [0159]    Step  207 , whether a confirming character returned from NFC chip is received in a preset time is determined, if yes, go to Step  208 ; otherwise, communication is failed and go back to Step  202 ; 
         [0160]    Step  208 , whether a trigger flag is set is determined, if yes, go to Step  210 ; otherwise, go to Step  209 ; 
         [0161]    Step  209 , data interrupting is waited for; go back to Step  208 ; 
         [0162]    In Embodiment 3, when the MCU receives data interrupting, data returned from the NFC chip is read, read data is checked, if the read data is setting work mode, state of the NFC chip and the return value of the token parameter, the work state of the token is updated to a first preset state and the trigger flag is set; if the read data is a return value of an obtaining data requirement, the work state of the token is updated as a second preset state and the trigger flag is set; 
         [0163]    Step  210 , the work state of the token is checked, if the work state is a first preset state, go to Step  211 ; if the work state is the second preset state, go to Step  214 ; 
         [0164]    Step  211 , the trigger flag is reset, whether a state parameter in the read data is a preset value is checked, if yes, a communication terminal is removed and communication is ended, go back to Step  202 ; otherwise, go to Step  212 ; 
         [0165]    In Embodiment 3, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0166]    Step  212 , the obtaining data requirement is sent to the NFC chip; 
         [0167]    In Embodiment 3, Step  212  specifically includes: generating and sending a receiving data instruction to the NFC chip; 
         [0168]    Preferably, in Embodiment 3, the receiving data instruction is TgGetData instruction. 
         [0169]    Step  213 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  208 ; otherwise, communication is failed, go back to Step  202 ; 
         [0170]    Step  214 , the trigger flag is reset, whether the state parameter in the received data is the preset value is checked, if yes, the communication terminal is removed, communication is ended, go back to Step  202 ; otherwise, go to Step  215 ; 
         [0171]    In Embodiment 3, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0172]    Step  215 , a dynamic password is sent to the NFC chip; 
         [0173]    in Embodiment 3, Step  215  specifically includes generating and sending a sending data instruction containing a dynamic password to the NFC chip; 
         [0174]    Preferably, in Embodiment 3, the sending data instruction is TgSetData instruction. 
         [0175]    In Embodiment 3, before Step  215 , the method further includes computing and generating the dynamic password; 
         [0176]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon a key and an event factor which are preset in the token, updating the event factor; or 
         [0177]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the key and the event factor which are preset in the token. 
         [0178]    Further, in Embodiment 3, when the MCU reads the return value of the obtaining data requirement returned from the NFC chip, the method further includes obtaining a challenge value from the return value of the obtaining data requirement; 
         [0179]    correspondingly, computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the event which are preset in the token, updating the event factor; or, 
         [0180]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key and the event which are preset in the token. 
         [0181]    Further, in Embodiment 3, Step  201  further includes: starting timer interrupting and setting interrupting priority of the timer interrupting to be the highest; 
         [0182]    correspondingly, in Embodiment 3, when the MCU receives the timer interrupting, the time factor preset in the new token is updated; 
         [0183]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the time factor which are preset in the token; or 
         [0184]    computing and generating the dynamic password specifically comprises: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor which are preset in the token; or, 
         [0185]    computing and generating the dynamic password specifically comprises: computing and generating the dynamic password upon the obtained challenge value, the key and the event factor which are preset in the token, and updating the event factor; or 
         [0186]    computing and generating the dynamic password specifically comprises: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key, the time factor and the event factor which are preset in the token. 
         [0187]    In Embodiment 3, before computing and generating the dynamic password, the method further comprises: prompting the user to input confirming generating dynamic password information, checking level of a key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, computing and generating the dynamic password, otherwise, going back to Step  202 . 
         [0188]    In Embodiment 3, before Step  215 , the method further comprises: prompting the user to input confirming sending password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, going to Step  215 ; otherwise, going back to Step  202 ; or before Step  215 , the method further comprises: prompting the user to input the confirming sending password information, waiting for receiving the key interrupting, determining whether the key interrupting is received in a preset time, if yes, going to Step  215 ; otherwise, going back to Step  202 . 
         [0189]    Step  216 , whether the confirming character returned from the NFC chip is received in a preset time, if yes, communication is successful, going back to Step  202 ; otherwise, communication is failed, going back to Step  202 . 
         [0190]    Further, in Embodiment 3, when the MCU receives the data interrupting, the method further comprises: if the read data is a return value of the sending dynamic password, setting the trigger flag; 
         [0191]    correspondingly, Step  216  is replaced with determining whether the confirming character returned from the NFC chip is received, if yes, going back to Step  208 ; otherwise, communication is failed and going back to Step  202 . 
       Embodiment 4 
       [0192]    Embodiment 4 provides a working method for an NFC token, which is as a target device and communicates with an initiator in passive mode. Referring to  FIG. 3 , the working method of the token specifically includes following steps performed by an MCU of the token. 
         [0193]    Step  301 , system initializing is performed; 
         [0194]    Step  302 , an NFC chip is reset; 
         [0195]    Specifically, in Embodiment 4, resetting the NFC chip includes: controlling, by the MCU, its MCU_SPI_RST pin to output low level and controlling its MCU_SPI_RST pin to output high level after delaying a preset time; 
         [0196]    Preferably, in Embodiment 4, before Step  302 , the method further includes: checking battery power and prompting that battery power is too low when the battery power is lower than a preset battery power; specifically, that battery power is too low is prompted by displaying on a screen and/or changing color of an indicator lamp and/or buzzing and/or voice. 
         [0197]    Step  303 , timeout limit of the NFC chip is set; 
         [0198]    Specifically, in Embodiment 4, setting the timeout limit of the NFC chip includes: sending, by the MCU, a setting timeout limit instruction to the NFC chip, the timeout limit instruction includes power up response timeout limit and communication timeout limit; 
         [0199]    Preferably, in Embodiment 4, setting timeout limit instruction is RFConfiguration instruction with Cfqlten parameter of 0x02. 
         [0200]    Step  304 , whether the setting timeout limit response returned from the NFC chip is received in a preset time is determined, if yes, go to Step  305 ; otherwise, communication is failed and go back to Step  302 ; 
         [0201]    Step  305 , whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response, if yes, go to Step  306 ; otherwise, communication is failed and go back to Step  302 ; 
         [0202]    Specifically, in Embodiment 4, whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response comprises: determining whether the data on the preset byte of the received setting timeout limit response is a preset character string, if yes, setting timeout limit of the NFC chip is successful, otherwise, setting the timeout limit of the NFC chip is failed; 
         [0203]    Preferably, in Embodiment 4, whether the data on the first three bytes of the received setting timeout limit response is 0x 00 00 FF is determined. 
         [0204]    Step  306 , the NFC chip is set as target state in passive mode and simulated card parameters are set and sent to the NFC chip; 
         [0205]    Specifically, in Embodiment 4, Step  306  includes: setting the parameters of the simulated card, generating a configuring target device instruction upon the set the simulated card parameters and sending the configuring target device instruction to the NFC chip; 
         [0206]    Preferably, in Embodiment 4, the configuring target device instruction is TgInitAsTarget instruction with Mode parameter of 0x04; the simulated card parameters include simulated card type and simulated card ID; for example, the simulated card type includes Felica card, Mifare card, etc. 
         [0207]    Step  307 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  308 ; otherwise, communication is failed and go back to Step  302 ; 
         [0208]    Step  308 , whether the NFC chip returns data is determined, if yes, go to Step  309 ; otherwise, go back to Step  308 ; 
         [0209]    in Embodiment 4, Step  308  specifically includes: waiting for data interrupting, executing Step  309  when the data interrupting is received; otherwise, waiting for data interrupting; or 
         [0210]    in Embodiment 4, Step  308  specifically includes: checking the level of the data interrupting pin, executing Step  309  if the level of the data interrupting pin is high level; otherwise, keeping on checking the level of the data interrupting pin. 
         [0211]    Step  309 , return data of the NFC chip is read, read data is checked; if the read data is the return value of setting the work mode, state and token parameters of the NFC chip, go to Step  310 ; if the return data is the return value of sending token parameters, go to Step  313 ; if the read data is a return value of an obtaining data requirement, go to Step  316 ; 
         [0212]    In Embodiment 4, the return data of setting the work mode, state and token parameters of the NFC chip specifically is a response of setting target device instruction; the return value of the obtaining data requirement specifically is response of the obtaining data requirement; 
         [0213]    Preferably, in Embodiment 4, the configuring target device instruction is TgInitAsTarget instruction with Mode parameter of 0x04; responding initiator instruction is TgResponseToInitiator instruction; obtaining data instruction is TgGetInitiator. 
         [0214]    Step  310 , whether a state parameter in the return value of setting NFC chip working mode, state and token parameter is a preset value, if yes, the communication terminal is removed and communication is ended, go back to Step  302 ; otherwise, go to Step  311 ; 
         [0215]    In Embodiment 4, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0216]    Step  311 , the token parameter is sent to the NFC chip; 
         [0217]    in Embodiment 4, Step  311  specifically includes: generating and sending the responding initiator instruction containing the token parameter to the NFC chip; 
         [0218]    Preferably, in Embodiment 4, the responding intiator instruction is TgResponseToInitiator instruction. 
         [0219]    Step  312 , whether the confirming character returned from the NFC chip is received in a preset time is determined, if yes, go back to Step  308 ; otherwise, communication is failed and go back to Step  302 ; 
         [0220]    Step  313 , whether the state parameter in the return value of sending token parameter is a preset value is checked, if yes, the communication terminal is removed and communication is ended, go back to Step  302 ; otherwise, go back to Step  314 ; 
         [0221]    in Embodiment 4, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0222]    Step  314 , sending the obtaining data requirement to the NFC chip; 
         [0223]    in Embodiment 4, Step  314  specifically includes: generating and sending an obtaining data instruction to the NFC chip; 
         [0224]    Preferably, in Embodiment 4, the obtaining data instruction is TgGetInitiator instruction. 
         [0225]    Step  315 , whether the confirming character returned from the NFC chip is received in a preset time is determined, if yes, go back to Step  308 ; otherwise, communication is failed, go back to Step  302 ; 
         [0226]    Step  316 , whether the state parameter in the return value of the obtaining data requirement is a preset value is checked, if yes, communication terminal is removed and communication is ended, go back to Step  302 ; otherwise, go to Step  317 ; 
         [0227]    in Embodiment 4, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0228]    Step  317 , a dynamic password is sent to the NFC chip; 
         [0229]    in Embodiment 4, Step  317  specifically includes: sending the responding initiator instruction containing the dynamic password to the NFC chip; 
         [0230]    Preferably, in Embodiment 4, the responding initiator instruction is TgResponseToInitiator instruction; 
         [0231]    In Embodiment 4, before Step  317 , the method further includes: computing and generating the dynamic password; 
         [0232]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon a key and an event factor which are preset in the token and updating the event factor; or, 
         [0233]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token and computing and generating the dynamic password upon the key and the event factor which are preset in the token; 
         [0234]    Further, in Embodiment 4, when the MCU reads the return value of the obtaining data requirement of the NFC chip, the method further includes obtaining a challenge value from the return value of the obtaining data requirement; 
         [0235]    correspondingly, computing and generating the dynamic password specifically includes: generating the dynamic password upon the obtained challenge value, the key and the event factor which are preset in the token and updating the event factor; or, 
         [0236]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key preset in the token and the event factor. 
         [0237]    Further, in Embodiment 4, Step  301  further includes: starting timer interrupting and setting interrupting priority of the timer interrupting to be the highest; 
         [0238]    Correspondingly, in Embodiment 4, when the MCU receives the timer interrupting, a time factor preset in the token is updated; 
         [0239]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the time factor which are preset in the token; or, 
         [0240]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor which are preset in the token; or, 
         [0241]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the event factor and the time factor which are preset in the token and updating the event factor; or 
         [0242]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key, the time factor and the event factor which are preset in the token. 
         [0243]    In Embodiment 4, computing and generating the dynamic password further includes: prompting the user to input confirming generating password information, checking whether the level of the key interrupting pin changes to be high level in a preset time, if yes, computing and generating the dynamic password, otherwise, go back to Step  302 ; or computing and generating the dynamic password further includes: prompting the user to input confirming generating password information, waiting for receiving key interrupting and determining whether the key interrupting is received in a preset time, if yes, computing and generating the dynamic password, otherwise, going back to Step  302 . 
         [0244]    In Embodiment 4, before Step  317 , the method further includes: prompting the user to input confirming sending password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, going to Step  317 ; otherwise, going back to Step  302 ; or before Step  317 , the method further includes: prompting the user to input confirming sending password information, waiting for receiving key interrupting and determining whether the key interrupting is received in a preset time, if yes, going to Step  317 ; otherwise, going back to Step  302 . 
         [0245]    Step  318 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, communication is successful, going back to Step  302 ; otherwise, communication is failed and going back to Step  302 . 
         [0246]    Further, in Embodiment 4, Step  309  further includes: if the read data is a return value of sending dynamic password, the state parameter of the return value of checking sending dynamic password is a preset value, if yes, communication terminal is removed and communication is ended, going back to Step  302 ; otherwise, going to Step  317 ; 
         [0247]    In Embodiment 4, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0248]    Correspondingly, Step  318  is replaced with determining whether a confirming character returned from the NFC chip is received in a preset time, if yes, going back to Step  308 ; otherwise, communication is failed, going back to Step  302 . 
       Embodiment 5 
       [0249]    Embodiment 5 provides a working method for an NFC token, which is as a target device and communicates with an initiator in passive mode. Referring to  FIG. 3 , the working method of the token specifically includes following steps performed by an MCU of the token. 
         [0250]    Step  401 , system initializing is performed; 
         [0251]    Step  402 , the NFC chip is reset, the work state of the token is set as initial state and a trigger flag is reset; 
         [0252]    specifically, in Embodiment 5, resetting the NFC chip includes: controlling, by an MCU, its MCU_SPI_RST pin to output low level; after a delayed preset time, controlling its MCU_SPI_RST pin to output high level; 
         [0253]    in Embodiment 5, before Step  402 , the method further includes: checking battery power and prompting that battery power is too low when the battery power is lower than a preset battery power; specifically, that battery power is too low is prompted by displaying on a screen and/or changing color of an indicator lamp and/or buzzing and/or voice. 
         [0254]    Step  403 , timeout limit of the NFC chip is set; 
         [0255]    Specifically, in Embodiment 5, setting the timeout limit of the NFC chip includes: sending, by the MCU, a setting timeout limit instruction to the NFC chip, the timeout limit instruction includes power up response timeout limit and communication timeout limit; 
         [0256]    Preferably, in Embodiment 5, setting timeout limit instruction is RFConfiguration instruction with Cfqlten parameter of 0x02. 
         [0257]    Step  404 , whether the setting timeout limit response returned from the NFC chip is received in a preset time is determined, if yes, go to Step  405 ; otherwise, communication is failed and go back to Step  402 ; 
         [0258]    Step  405 , whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response, if yes, go to Step  406 ; otherwise, communication is failed and go back to Step  402 ; 
         [0259]    Specifically, in Embodiment 5, whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response includes: determining whether the data on the preset byte of the received setting timeout limit response is a preset character string, if yes, setting timeout limit of the NFC chip is successful, otherwise, setting the timeout limit of the NFC chip is failed; 
         [0260]    Preferably, in Embodiment 5, whether the data on the first three bytes of the received setting timeout limit response is 0x 00 00 FF is determined. 
         [0261]    Step  406 , the NFC chip is set as target state in passive mode and simulated card parameters are set and sent to the NFC chip; 
         [0262]    specifically, in Embodiment 5, Step  406  includes: setting the parameters of the simulated card, generating a configuring target device instruction upon the set the simulated card parameters and sending the configuring target device instruction to the NFC chip; 
         [0263]    preferably, in Embodiment 5, the configuring target device instruction is TgInitAsTarget instruction with Mode parameter of 0x04; the simulated card parameters include simulated card type and simulated card ID; for example, the simulated card type includes Felica card, Mifare card, etc. 
         [0264]    Step  407 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  408 ; otherwise, communication is failed and go back to Step  402 ; 
         [0265]    Step  408 , whether a trigger flag is set is determined, if yes, go to Step  410 ; otherwise, go to Step  409 ; 
         [0266]    Step  409 , data interrupting is waited for; go back to Step  208 ; 
         [0267]    In Embodiment 5, when the MCU receives data interrupting, data returned from the NFC chip is read, read data is checked, if the read data is setting work mode, state of the NFC chip and the return value of the token parameter, the work state of the token is updated to a first preset state and the trigger flag is set; if the read data is a return value of an obtaining data requirement, the work state of the token is updated as a second preset state and the trigger flag is set; 
         [0268]    In Embodiment 5, the return data of setting the work mode, state and token parameters of the NFC chip specifically is a response of setting target device instruction; the return value of obtaining data requirement specifically is response of obtaining data requirement; 
         [0269]    Preferably, in Embodiment 5, the configuring target device instruction is TgInitAsTarget instruction; responding initiator instruction is TgResponseToInitiator instruction; the return value of obtaining data requirement is response of TgGetInitiator instruction. 
         [0270]    Step  410 , the work state of the token is checked, if the work state is a third state, go to Step  411 ; if the work state is a first preset state, go to Step  414 ; if the work state is the second preset state, go to Step  417 ; 
         [0271]    Step  411 , the trigger flag is reset, whether a state parameter in the received data is a preset value is checked, if yes, a communication terminal is removed and communication is ended, go back to Step  402 ; otherwise, go to Step  412 ; 
         [0272]    In Embodiment 5, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0273]    Step  412 , the token parameter is sent to the NFC chip; 
         [0274]    in Embodiment 5, Step  412  specifically includes: generating and sending the responding initiator instruction containing the token parameter to the NFC chip; 
         [0275]    Preferably, in Embodiment 5, the responding initiator instruction is TgResponseToInitiator instruction. 
         [0276]    Step  413 , whether the confirming character returned from the NFC chip is received in a preset time is determined, if yes, go back to Step  408 ; otherwise, communication is failed and go back to Step  402 ; 
         [0277]    Step  414 , the trigger flag is reset; whether the state parameter in the received data is a preset value is checked, if yes, the communication terminal is removed and communication is ended, go back to Step  402 ; otherwise, go back to Step  415 ; 
         [0278]    in Embodiment 5, the state parameter specifically is status, the preset value specifically is 0x29. 
         [0279]    Step  415 , sending the obtaining data requirement to the NFC chip; 
         [0280]    in Embodiment 5, Step  415  specifically includes: generating and sending an obtaining data instruction to the NFC chip; 
         [0281]    Preferably, in Embodiment 5, the obtaining data instruction is TgGetInitiator instruction. 
         [0282]    Step  416 , whether the confirming character returned from the NFC chip is received in a preset time is determined, if yes, go back to Step  408 ; otherwise, communication is failed, go back to Step  402 ; 
         [0283]    Step  417 , the trigger flag is reset, whether a state parameter in the received data is a preset value is checked, if yes, a communication terminal is removed and communication is ended, go back to Step  402 ; otherwise, go to Step  418 ; 
         [0284]    In Embodiment 5, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0285]    Step  418 , a dynamic password is sent to the NFC chip; 
         [0286]    In Embodiment 5, Step  418  specifically includes: sending the responding initiator instruction containing the dynamic password to the NFC chip; 
         [0287]    Preferably, in Embodiment 5, the responding initiator instruction is TgResponseToInitiator instruction; 
         [0288]    in Embodiment 5, before Step  418 , the method further includes: computing and generating the dynamic password; 
         [0289]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon a key and an event factor which are preset in the token and updating the event factor; or, 
         [0290]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token and computing and generating the dynamic password upon the key and the event factor which are preset in the token; 
         [0291]    further, in Embodiment 5, when the MCU reads the return value of the obtaining data requirement of the NFC chip, the method further includes obtaining a challenge value from the return value of the obtaining data requirement; 
         [0292]    correspondingly, computing and generating the dynamic password specifically includes: generating the dynamic password upon the obtained challenge value, the key and the event factor which are preset in the token and updating the event factor; or, 
         [0293]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key and the event factor which are preset in the token. 
         [0294]    Further, in Embodiment 5, Step  401  can further include: starting timer interrupting and setting interrupting priority of the timer interrupting to be the highest; 
         [0295]    correspondingly, in Embodiment 5, when the MCU receives the timer interrupting, a time factor preset in the token is updated; 
         [0296]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the time factor which are preset in the token; or, 
         [0297]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor which are preset in the token; or 
         [0298]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the event factor and the time factor which are preset in the token; and updating the event factor; or, 
         [0299]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key, the time factor and the event factor which are preset in the token. 
         [0300]    In Embodiment 5, computing and generating the dynamic password further includes: prompting the user to input confirming generating password information, checking whether the level of the key interrupting pin changes to be high level in a preset time, if yes, computing and generating the dynamic password, otherwise, go back to Step  402 ; or computing and generating the dynamic password further includes: prompting the user to input confirming generating password information, waiting for receiving key interrupting and determining whether the key interrupting is received in a preset time, if yes, computing and generating the dynamic password, otherwise, going back to Step  402 . 
         [0301]    In Embodiment 5, before Step  418 , the method further includes: prompting the user to input confirming sending password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, going to Step  418 ; otherwise, going back to Step  402 ; or before Step  418 , the method further includes: prompting the user to input confirming sending password information, waiting for receiving key interrupting and determining whether the key interrupting is received in a preset time, if yes, going to Step  418 ; otherwise, going back to Step  402 . 
         [0302]    Step  419 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, communication is successful, going back to Step  402 ; otherwise, communication is failed and going back to Step  402 . 
         [0303]    Further, in Embodiment 5, when the MCU receives data interrupting, the method further includes: setting the trigger flag if the read data is the return value of sending dynamic password; 
         [0304]    Correspondingly, Step  419  is replaced with determining whether a confirming character returned from the NFC chip is received in a preset time, if yes, go back to Step  408 ; otherwise, communication is failed, go back to Step  402 . 
       Embodiment 6 
       [0305]    Embodiment 6 provides a working method for an NFC token, which is as a target device and communicates with an initiator in passive mode. Referring to  FIG. 6 , the working method of the token specifically includes following steps performed by an MCU of the token. 
         [0306]    Step  501 , system initializing is performed; 
         [0307]    Step  502 , an NFC chip is reset; 
         [0308]    specifically, in Embodiment 6, resetting the NFC chip includes: controlling, by an MCU, its MCU_SPI_RST pin to output low level; after a delayed preset time, controlling its MCU_SPI_RST pin to output high level; 
         [0309]    preferably, in Embodiment 6, before Step  502 , the method further includes: checking battery power and prompting that battery power is too low when the battery power is lower than a preset battery power; specifically, that battery power is too low is prompted by displaying on a screen and/or changing color of an indicator lamp and/or buzzing and/or voice. 
         [0310]    Step  503 , timeout limit of the NFC chip is set; 
         [0311]    Specifically, in Embodiment 6, setting the timeout limit of the NFC chip includes: sending, by the MCU, a setting timeout limit instruction to the NFC chip, the timeout limit instruction includes power up response timeout limit and communication timeout limit; 
         [0312]    Preferably, in Embodiment 6, setting timeout limit instruction is RFConfiguration instruction with Cfqlten parameter of 0x02. 
         [0313]    Step  504 , whether a setting timeout limit response returned from the NFC chip is received in a preset time is determined, if yes, go to Step  505 ; otherwise, communication is failed and go back to Step  502 ; 
         [0314]    Step  505 , whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response, if yes, go to Step  506 ; otherwise, communication is failed and go back to Step  502 ; 
         [0315]    Specifically, in Embodiment 6, whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response includes: determining whether the data on the preset byte of the received setting timeout limit response is a preset character string, if yes, setting timeout limit of the NFC chip is successful, otherwise, setting the timeout limit of the NFC chip is failed; 
         [0316]    Preferably, in Embodiment 6, whether the data on the first three bytes of the received setting timeout limit response is 0x 00 00 FF is determined. 
         [0317]    Step  506 , the NFC chip is set as initiator state in passive mode, type and rate of a card to be searched is set and sent to the NFC chip; 
         [0318]    Specifically, in Embodiment 6, Step  506  includes: initializing a configuration initiator instruction, setting the type and the rate of the card to be searched, setting the card searching parameters in the initiator instruction upon the type and rate of the card to be searched, sending the configuration initiator instruction to the NFC chip; 
         [0319]    Preferably, in Embodiment 6, the configuration initiator instruction is InLisPassiveTarget instruction. Step  506  includes: initializing InLisPassiveTarget instruction, setting the type and rate of the card to be searched; setting BrTy parameter of the InLisPassiveTarget instruction upon the type and rate of the card to be searched, sending the InLisPassiveTarget instruction to the NFC chip; 
         [0320]    For example, if the set type and rate of the card to be searched are A type card and 106 kbps of ISO/IEC14443 protocol, BrTy parameter of the InLisPassiveTarget instruction is set as 0x00; 
         [0321]    if the set type and rate of the card to be searched are FeliCa polling card and 212 kbps, BrTy parameter of the InLisPassiveTarget instruction is set as 0x01; 
         [0322]    if the set type and rate of the card to be searched are FeliCa polling card and 424 kbps, BrTy parameter of the InLisPassiveTarget instruction is set as 0x02; 
         [0323]    if the set type and rate of the card to be searched are B type card and 106 kbps of ISO/IEC14443-3 protocol, BrTy parameter of the InLisPassiveTarget instruction is set as 0x03; 
         [0324]    if the set type and rate of the card to be searched are Innovision Jewel tag card and 106 kbps, BrTy parameter of the InLisPassiveTarget instruction is set as 0x04. 
         [0325]    Step  507 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  508 ; otherwise, communication is failed and go back to Step  502 ; 
         [0326]    Step  508 , whether data returned from the NFC chip exists is determined, if yes, go to Step  509 ; otherwise, go back to Step  508 ; 
         [0327]    in Embodiment 6, Step  508  specifically includes: waiting for data interrupting, executing Step  509  when the data interrupting is received; otherwise, waiting for data interrupting; or 
         [0328]    in Embodiment 6, Step  508  specifically includes: checking the level of the data interrupting pin, executing Step  509  if the level of the data interrupting pin is high level; otherwise, keeping on checking the level of the data interrupting pin. 
         [0329]    Step  509 , return data of the NFC chip is read and read data is checked; if the read data is a return value of setting the work mode, state and token parameters of the NFC chip, go to Step  510 ; if the read data is a return value of an obtaining data requirement, go to Step  513 ; 
         [0330]    In Embodiment 6, the return data of setting the work mode, state and token parameters of the NFC chip specifically is a response of the configuration initiator instruction; the return value of the obtaining data requirement specifically is a return value of a data exchange instruction; 
         [0331]    Preferably, in Embodiment 6, the configuration initiator instruction is InLisPassiveTarget instruction and the data exchange instruction is InDataExchange instruction. 
         [0332]    Step S 10 , whether the state parameter in the return value of setting NFC chip working mode, state and token parameter is a preset value is checked; if yes, a communication terminal is removed, communication is ended and go back to Step  102 ; otherwise, execute Step  511 ; 
         [0333]    In Embodiment 6, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0334]    Step  511 , the obtaining data requirement is sent to the NFC chip; 
         [0335]    In Embodiment 6, Step  511  specifically includes: generating and sending the data exchange instruction to the NFC chip; 
         [0336]    Preferably, in Embodiment 6, the data exchange instruction is InDataExchange instruction. 
         [0337]    Step S 12 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  508 ; otherwise, communication is failed and go back to Step  502 ; 
         [0338]    Step  513 , whether a state parameter in the return value of the obtaining data requirement is a preset value is checked, if yes, the communication terminal is removed and communication is ended, go back to Step  502 ; otherwise, go to Step  514 ; 
         [0339]    in Embodiment 6, the state parameter specifically is status; the preset value specifically is 0x29. 
         [0340]    Step  514 , a dynamic password is sent to the NFC chip; 
         [0341]    In Embodiment 6, Step  514  specifically includes: generating and sending the data exchanging instruction containing the dynamic password to the NFC chip; 
         [0342]    Preferably, in Embodiment 6, the data exchanging instruction is InDataExchange instruction. 
         [0343]    In Embodiment 6, before Step  514 , the method further includes computing and generating the dynamic password; 
         [0344]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon a key and an event factor which are preset in the token, and updating the event factor; or 
         [0345]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token and computing and generating the dynamic password upon the key and the event factor which are preset in the token. 
         [0346]    Further, in Embodiment 6, when the MCU reads the return value of the obtaining data requirement returned from the NFC chip, the method further includes obtaining the challenge value from the return value of the obtaining data requirement and displaying the challenge value; 
         [0347]    correspondingly, computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and event factor which are preset in the token, updating the event factor; or 
         [0348]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, and the key and the event factor which are preset in the token. 
         [0349]    Further, in Embodiment 6, Step  501  can further include: starting timer interrupting and setting interrupting priority of the timer interrupting to be highest; 
         [0350]    correspondingly, in Embodiment 6, when the MCU receives the timer interrupting, a timer factor preset in the token is updated; 
         [0351]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the time factor which are preset in the token. Or, 
         [0352]    computing and generating the dynamic password includes: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor which are preset in the token; or 
         [0353]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor and the event factor which are preset in the token; or 
         [0354]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password upon the obtained challenge value, the key and the time factor and the event factor which are preset in the token. 
         [0355]    In Embodiment 6, before computing and generating the dynamic password, the method further includes: prompting the user to input confirming generating password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time; if yes, computing and generating the dynamic password; otherwise, go back to Step  502 ; or the method includes: prompting the user to input the confirming generating password information, waiting for receiving the key interrupting and determining whether the key interrupting is received in a preset time, if yes, computing and generating the dynamic password; otherwise, go back to Step  502 . 
         [0356]    In Embodiment 6, before Step  514 , the method further comprises: prompting the user to input confirming sending password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, going to Step  514 ; otherwise, going back to Step  502 ; or before Step  514 , the method further comprises: prompting the user to input the confirming sending password information, waiting for receiving the key interrupting, determining whether the key interrupting is received in a preset time, if yes, going to Step  514 ; otherwise, going back to Step  502 . 
         [0357]    Step  515 , whether the confirming character returned from the NFC chip is received in a preset time, if yes, communication is successful, going back to Step  502 ; otherwise, communication is failed, going back to Step  502 . 
         [0358]    Further, in Embodiment 6, Step  509  further includes: if the read data is the return value of sending dynamic password, checking whether the state parameter in the return value of sending the dynamic password is the preset value, if yes, the communication terminal is removed and communication is ended, going back to Step  502 ; otherwise, going to Step  514 ; 
         [0359]    In Embodiment 6, the state parameter specifically is status and the preset value specifically is 0x29. 
         [0360]    Correspondingly, Step  515  is replaced with determining whether the confirming character returned from the NFC chip is received in a preset time, if yes, going back to Step  508 ; otherwise, communication is failed and going back to Step  502 . 
       Embodiment 7 
       [0361]    Embodiment 7 provides a working method for an NFC token, which is as a target device and communicates with an initiator in passive mode. Referring to  FIG. 7 , the working method of the token specifically includes following steps performed by an MCU of the token. 
         [0362]    Step  601 , system initializing is performed; 
         [0363]    Step  602 , the NFC chip is reset, the work state of the token is set as initial state and a trigger flag is reset; 
         [0364]    specifically, in Embodiment 7, resetting the NFC chip includes: controlling, by an MCU, its MCU_SPI_RST pin to output low level; after a delayed preset time, controlling its MCU_SPI_RST pin to output high level; 
         [0365]    preferably, in Embodiment 7, before Step  602 , the method further includes: checking battery power and prompting that battery power is too low when the battery power is lower than a preset battery power; specifically, that battery power is too low is prompted by displaying on a screen and/or changing color of an indicator lamp and/or buzzing and/or voice. 
         [0366]    Step  603 , timeout limit of the NFC chip is set; 
         [0367]    Specifically, in Embodiment 7, setting the timeout limit of the NFC chip includes: sending, by the MCU, a setting timeout limit instruction to the NFC chip, the timeout limit instruction includes power up response timeout limit and communication timeout limit; 
         [0368]    Preferably, in Embodiment 7, setting timeout limit instruction is RFConfiguration instruction with Cfqlten parameter of 0x02. 
         [0369]    Step  604 , whether the setting timeout limit response returned from the NFC chip is received in a preset time is determined, if yes, go to Step  605 ; otherwise, communication is failed and go back to Step  602 ; 
         [0370]    Step  605 , whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response, if yes, go to Step  606 ; otherwise, communication is failed and go back to Step  602 ; 
         [0371]    Specifically, in Embodiment 7, whether the timeout limit of the NFC chip is set successfully is determined upon the set timeout limit response includes: determining whether the data on the preset byte of the received setting timeout limit response is a preset character string, if yes, setting timeout limit of the NFC chip is successful, otherwise, setting the timeout limit of the NFC chip is failed; 
         [0372]    Preferably, in Embodiment 7, whether the data on the first three bytes of the received setting timeout limit response is 0x 00 00 FF is determined. 
         [0373]    Step  606 , the NFC chip is set as initiator state in passive mode, type and rate of a card to be searched is set and sent to the NFC chip; 
         [0374]    Specifically, in Embodiment 7, Step  606  includes: initializing a configuration initiator instruction, setting the type and the rate of the card to be searched, setting the card searching parameters in the initiator instruction upon the type and rate of the card to be searched, sending the configuration initiator instruction to the NFC chip; 
         [0375]    Preferably, in Embodiment 7, the configuration initiator instruction is InLisPassiveTarget instruction. Step  506  includes: initializing InLisPassiveTarget instruction, setting the type and rate of the card to be searched; setting BrTy parameter of the InLisPassiveTarget instruction upon the type and rate of the card to be searched, sending the InLisPassiveTarget instruction to the NFC chip; 
         [0376]    For example, if the set type and rate of the card to be searched are A type card and 106 kbps of ISO/IEC14443 protocol, BrTy parameter of the InLisPassiveTarget instruction is set as 0x00; 
         [0377]    if the set type and rate of the card to be searched are FeliCa polling card and 212 kbps, BrTy parameter of the InLisPassiveTarget instruction is set as 0x01; 
         [0378]    if the set type and rate of the card to be searched are FeliCa polling card and 424 kbps, BrTy parameter of the InLisPassiveTarget instruction is set as 0x02; 
         [0379]    if the set type and rate of the card to be searched are B type card and 106 kbps of ISO/IEC14443-3 protocol, BrTy parameter of the InLisPassiveTarget instruction is set as 0x03; 
         [0380]    if the set type and rate of the card to be searched are Innovision Jewel tag card and 106 kbps, BrTy parameter of the InLisPassiveTarget instruction is set as 0x04. 
         [0381]    Step  607 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go to Step  608 ; otherwise, communication is failed and go back to Step  602 ; 
         [0382]    Step  608 , whether the trigger flag is set is checked, if yes, go to Step  610 ; otherwise, go back to Step  609 ; 
         [0383]    Step  609  specifically includes: waiting for data interrupting, going back to Step  608 ; 
         [0384]    In Embodiment 7, when the MCU receives data interruption, reading return data of the NFC chip, checking the read data, if the read data is a return value of setting work mode, state and token parameter of the NFC chip, the work state of the token is updated to a first preset state and the trigger flag is set; if the read data is a return value of an obtaining data requirement, the work state of the token is updated to a second preset state and the trigger flag is set; 
         [0385]    In Embodiment 7, setting return value of setting work mode, state and token parameter of the NFC chip specifically is a response of configuring initiator instruction; the return value of the obtaining data requirement specifically is a response of a data exchange instruction; 
         [0386]    Preferably, in Embodiment 7, the configuring initiator instruction is InLisPassiveTarget instruction and the data exchange instruction is InDataExchange instruction. 
         [0387]    Step  610 , work state of the token is checked, go to Step  611  if the work state is a first preset state; go to Step  614  if the work state is the second preset state; 
         [0388]    Step  611 , the trigger flag is set; whether the state parameter in the received data is a preset value is checked, if yes, a communication terminal is removed and communication is ended, go back to Step  602 ; otherwise, go to Step  612 ; 
         [0389]    In Embodiment 7, the state parameter is status and the preset value specifically is 0x29. 
         [0390]    Step  612 , the obtaining data requirement is sent to the NFC chip; 
         [0391]    in Embodiment 7, Step  612  specifically includes: generating and sending the data exchange instruction to the NFC chip; 
         [0392]    preferably, in Embodiment 7, the data exchange instruction is InDataExchange instruction. 
         [0393]    Step  613 , whether a confirming character returned from the NFC chip is received in a preset time is determined, if yes, go back to Step  608 ; otherwise, communication is failed and go back to Step  602 ; 
         [0394]    Step  614 , the trigger flag is reset; whether the state parameter in the received data is a preset value is checked, if yes, the communication terminal is removed and communication is ended, go back to Step  602 ; otherwise, go to Step  615 ; 
         [0395]    In Embodiment 7, the state parameter specifically is status and the preset value specifically is 0x29. 
         [0396]    Step  615 , a dynamic password is sent to the NFC chip; 
         [0397]    in Embodiment 7, Step  615  specifically includes: generating and sending the data exchange instruction containing the dynamic password to the NFC chip; 
         [0398]    preferably, in Embodiment 7, the data exchange instruction is InDataExchange instruction. 
         [0399]    In Embodiment 7, before Step  615 , the method further includes: computing and generating the dynamic password, 
         [0400]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the event factor preset in the token and updating the event factor; or 
         [0401]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token and computing and generating the dynamic password upon the key and the event factor preset in the token; 
         [0402]    further, in the present Embodiment 7, when the MCU reads the return value of obtaining data requirement returned from the NFC chip, the method further includes obtaining a challenge value from the return value of the obtaining data requirement; 
         [0403]    correspondingly, computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the obtained challenge value, the key and the event factor which are preset in the token, updating the event factor; or, 
         [0404]    computing and generating the dynamic password specifically includes: updating the event factor preset in the token, computing and generating the dynamic password. 
         [0405]    Further, in Embodiment 7, Step  601  further includes: starting timer interrupting, setting interrupting priority of the timer interrupting to be highest; 
         [0406]    correspondingly, in Embodiment 7, when the MCU receives the timer interrupting, a timer factor preset in the token is updated; 
         [0407]    computing and generating the dynamic password specifically includes: computing and generating the dynamic password upon the key and the time factor which are preset in the token; or, 
         [0408]    computing and generating the dynamic password includes: computing and generating the dynamic password upon the obtained challenge value, the key and the time factor which are preset in the token; or 
         [0409]    computing and generating the dynamic password specifically includes computing and generating the dynamic password upon the obtained challenge value, the key and the event factor and the time factor which are preset in the token, and updating the event factor; or 
         [0410]    computing and generating the dynamic password specifically includes computing and generating the dynamic password upon the obtained challenge value, the key and the event factor and the time factor which are preset in the token, and updating the event factor; 
         [0411]    in Embodiment 7, before computing and generating the dynamic password, the method further includes: prompting the user to input confirming generating password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time; if yes, computing and generating the dynamic password; otherwise, go back to Step  602 ; or the method includes: prompting the user to input the confirming generating password information, waiting for receiving the key interrupting and determining whether the key interrupting is received in a preset time, if yes, computing and generating the dynamic password; otherwise, go back to Step  602 . 
         [0412]    In Embodiment 7, before Step  615 , the method further includes: prompting the user to input the confirming sending password information, checking the level of the key interrupting pin, determining whether the level of the key interrupting pin changes to be high level in a preset time, if yes, go to Step  615 ; otherwise, go back to Step  602 ; or the method includes: prompting the user to input the confirming sending password information, waiting for receiving the key interrupting and determining whether the key interrupting is received in the preset time, if yes, go to Step  615 ; otherwise, go back to Step  602 . 
         [0413]    Step  616 , whether the confirming character returned from the NFC chip is received in a preset time is determined, if yes, communication is successful, go back to Step  602 ; otherwise, communication is failed, go back to Step  602 . 
         [0414]    Further, in Embodiment 7, when the MCU receives the data interrupting, the method further includes: if the read data is a return value of sending the dynamic password, setting the trigger flag; 
         [0415]    correspondingly, Step  616  is replaced by determining whether a confirming character returned from the NFC chip is received in a preset time, if yes, going back to Step  608 ; otherwise, communication is failed and going back to Step  602 . 
         [0416]    The described embodiments are only preferred embodiments of the invention and the embodiments are not intended to limit the invention. Any alteration or change easily obtained by those skilled in the art based on the invention should fall in the scope of protection of the invention.