Communication Apparatus and Communication Method

• US 20080258864A1
• Filed: 10/28/2004
• Published: 10/23/2008
• Est. Priority Date: 10/28/2004
• Status: Abandoned Application

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Yamada, Keiki, Kamemaru, Toshihisa, Nishikawa, Koji, Hattori, Takashi
• Application Number:
  US11/663,354
• Publication Number:
  US 20080258864A1
• Time in Patent Office: Days
• US Class Current: 340/5.8
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10029 the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/3215 using a plurality of channels network architectures or network communication protocols using different networks H04L63/18
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 12/06 Authentication

Abstract

A communication apparatus for mutual communication, when acting as an authenticator communication apparatus performing authentication, includes a transmitting section that transmits to an authenticatee communication apparatus subject to authentication challenge data to authenticate the authenticatee communication apparatus in a time slot, which is a segmented period of time in which the communication apparatus to communicate with a specific communication apparatus; and a receiving section that receives from the authenticatee communication apparatus first response data for responding to the challenge data in the same time slot as the one in which the transmitting section transmits the challenge data. An objective is to carry out authentication of a tag by a Reader/Writer (R/W) and authentication of the R/W by the tag at the same time as an anti-collision process, and to further achieve confidentiality of unique ID information that is transmitted.

Claims

1. A communication apparatus for mutual communication,

when the communication apparatus is an authenticator communication apparatus that performs authentication,

the communication apparatus comprising:

a transmitting section that transmits challenge data to authenticate an authenticatee communication apparatus that is subject to authentication to the authenticatee communication apparatus in a period allocated before a first time slot of time slots that are segmented periods of time in which the communication apparatus is able to use a single communication channel by time division; and

a receiving section that receives from the authenticatee communication apparatus first response data for responding to the challenge data in a time slot provided after the first time slot, and

when the communication apparatus is the authenticatee communication apparatus that is subject to authentication,

the communication apparatus comprising;

a receiving section that receives the challenge data to authenticate the authenticatee communication apparatus from the authenticator communication apparatus that performs authentication in a period allocated before the first time slot of the time slots that are segmented periods of time in which the communication apparatus is able to use a single communication channel by time division; and

a transmitting section that transmits to the authenticator communication apparatus the first response data for responding to the challenge data in a time slot provided after the first time slot.

5. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

a data processing section that processes at least part of the challenge data transmitted by the transmitting section and generates new data, and

when the communication apparatus is the authenticatee communication apparatus,

the communication apparatus further comprising;

a data processing section that processes at least part of the challenge data received by the receiving section and generates new data.

8. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

an authenticating section that authenticates the authenticatee communication apparatus by using at least part of the challenge data transmitted by the transmitting section and at least part of the first response data received by the receiving section.

11. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

a connecting section that connects a communication channel with the authenticatee communication apparatus in a same time slot as the time slot in which the receiving section receives the first response data.

12. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

a data storing section that stores at least part of the challenge data transmitted by the transmitting section and at least part of the first response data received by the receiving section;

a data determining section that determines whether one of the at least part of the challenge data and the at least part of the first response data stored in the data storing section matches at least part of first response data newly received by the receiving section;

wherein the transmitting section performs one of not transmitting second response data and transmitting second response data for causing the authenticatee communication apparatus to detect a communication error, when the data determining section determines that they match, and

when the communication apparatus is the authenticatee communication apparatus that is subject to authentication,

the communication apparatus further comprising;

a data storing section that stores at least part of the challenge data received by the receiving section and at least part of the first response data transmitted by the transmitting section;

a data determining section that determines whether one of the at least part of the challenge data and the at least part of the first response data stored in the data storing section matches at least part of challenge data newly received by the receiving section;

wherein the transmitting section performs one of not transmitting new first response data and transmitting new first response data for causing the authenticator communication apparatus to detect a communication error, when the data determining section determines that they match.

13. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

an authenticating section that authenticates the authenticatee communication apparatus by using at least part of the challenge data transmitted by the transmitting section and at least part of the first response data received by the receiving section;

a detecting section that detects a communication error by using at least part of the first response data received by the receiving section;

a data storing section that stores at least part of the challenge data transmitted by the transmitting section and at least part of the first response data received by the receiving section;

a data determining section that determines whether one of the at least part of the challenge data and the at least part of the first response data stored in the data storing section matches at least part of first response data newly received by the receiving section;

a condition storing section that stores conditions on;

a number of times the authenticating section determines that the authenticatee communication apparatus is not a right communication apparatus;

a number of times the detecting section detects a communication error; and

a number of times the data determining section determines that they do not match;

a condition determining section that determines whether at least one of the number of times the authenticating section determines that the authenticatee communication apparatus is not the right communication apparatus, the number of times the detecting section detects a communication error, and the number of times the data determining section determines that they do not match satisfies the conditions stored in the condition storing section; and

a notifying section that notifies a managing device that manages the communication apparatus of a result of determination by the condition determining section.

14. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

at least one of an encrypting section that encrypts data and a decrypting section that decrypts data;

a random number generating section that generates a random number of the authenticator communication apparatus; and

an own equipment identifier storing section that stores an identifier of the authenticator communication apparatus,

wherein the encrypting section encrypts the random number of the authenticator communication apparatus generated by the random number generating section to generate an encrypted random number of the authenticator communication apparatus, and also encrypts the identifier of the authenticator communication apparatus stored in the own equipment identifier storing section by using the encrypted random number of the authenticator communication apparatus to generate an encrypted identifier of the authenticator communication apparatus, wherein the decrypting section decrypts the random number of the authenticator communication apparatus generated by the random number generating section to generate a decrypted random number of the authenticator communication apparatus, and also decrypts the identifier of the authenticator communication apparatus stored in the own equipment identifier storing section by using the decrypted random number of the authenticator communication apparatus to generate a decrypted identifier of the authenticator communication apparatus,

wherein the transmitting section transmits the challenge data including one of a set of the encrypted random number of the authenticator communication apparatus and the encrypted identifier of the authenticator communication apparatus generated by the encrypting section, and a set of the decrypted random number of the authenticator communication apparatus and the decrypted identifier of the authenticator communication apparatus generated by the decrypting section, and

when the communication apparatus is the authenticatee communication apparatus,

the communication apparatus further comprising;

at least one of an encrypting section that encrypts data and a decrypting section that decrypts data; and

an own equipment identifier storing section that stores an identifier of the authenticatee communication apparatus,

wherein the encrypting section further encrypts the random number of the authenticator communication apparatus obtained by encrypting the decrypted random number of the authenticator communication apparatus included in the challenge data received by the receiving section to generate an encrypted random number of the authenticator communication apparatus, and also encrypts the identifier of the authenticatee communication apparatus stored in the own equipment identifier storing section by using the encrypted random number of the authenticator communication apparatus to generate an encrypted identifier of the authenticatee communication apparatus,

wherein the decrypting section further decrypts the random number of the authenticator communication apparatus obtained by decrypting the encrypted random number of the authenticator communication apparatus included in the challenge data received by the receiving section to generate a decrypted random number of the authenticator communication apparatus, and also decrypts the identifier of the authenticatee communication apparatus stored in the own equipment identifier storing section by using the decrypted random number of the authenticator communication apparatus to generate a decrypted identifier of the authenticatee communication apparatus, and

wherein the transmitting section transmits the first response data including one of a set of the encrypted random number of the authenticator communication apparatus and the encrypted identifier of the authenticatee communication apparatus generated by the encrypting section and a set of the decrypted random number of the authenticator communication apparatus and the decrypted identifier of the authenticatee communication apparatus generated by the decrypting section.

16. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

an opposed equipment identifier storing section that stores an identifier of a communication apparatus to be authenticated and an identifier of a communication apparatus not to be authenticated, and

an opposed equipment identifier determining section that determines whether an identifier stored in the opposed equipment identifier storing section matches an identifier of the authenticatee communication apparatus included in first response data newly received by the receiving section,

wherein the transmitting section transmits second response data to the authenticatee communication apparatus in one of cases;

where the opposed equipment identifier determining section determines that the identifier of the communication apparatus to be authenticated stored in the opposed equipment identifier storing section matches the identifier of the authenticatee communication apparatus included in the first response dada newly received by the receiving section, and

where the opposed equipment identifier determining section determines that the identifier of the communication apparatus not to be authenticated stored in the opposed equipment identifier storing section does not match the identifier of the authenticatee communication apparatus included in the first response data newly received by the receiving section,

when the communication apparatus is the authenticatee communication apparatus,

the communication apparatus further comprising;

an opposed equipment identifier storing section that stores an identifier of a communication apparatus to be responded and an identifier of a communication apparatus not to be responded, and

an opposed equipment identifier determining section that determines whether an identifier stored in the opposed equipment identifier storing section and an identifier of the authenticator communication apparatus included in challenge data newly received by the receiving section,

wherein the transmitting section transmits the first response data to the authenticator communication apparatus in one of cases;

where the opposed equipment identifier determining section determines that the identifier of the communication apparatus to be responded stored in the opposed equipment identifier storing section matches the identifier of the authenticator communication apparatus included in the challenge dada newly received by the receiving section, and

where the opposed equipment identifier determining section determines that the identifier of the communication apparatus not to be responded stored in the opposed equipment identifier storing section does not match the identifier of the authenticator communication apparatus included in the challenge data newly received by the receiving section.

17. The communication apparatus of any one of claim 1,

when the communication apparatus is the authenticatee communication apparatus,

the communication apparatus further comprising:

a detecting section that detects a communication error by using at least part of the challenge data received by the receiving section from the authenticatee communication apparatus; and

a reporting section that makes a report about a result of detection of the communication error detected by the detecting section.

18. The communication apparatus of claim 1 forming one of a Radio Frequency Identification (RFID) system, a Local Area Network (LAN), and a Bluetooth system, and storing a unique identifier to identify the communication apparatus.

19. The communication apparatus of claim 1,

when the communication apparatus is the authenticator communication apparatus,

the communication apparatus further comprising:

an opposed equipment identifier processing section that processes a source identifier and generate a new identifier with treating an identifier of the authenticatee communication apparatus included in the first response data received by the receiving section as an original source identifier and the new identifier generated as a next source identifier, and

when the communication apparatus is the authenticatee communication apparatus,

the communication apparatus further comprising;

an opposed equipment identifier processing section that processes a source identifier and generate a new identifier with treating an identifier of the authenticator communication apparatus included in the challenge data received by the receiving section as an original source identifier and the new identifier generated as a next source identifier.

2. (canceled)

3. A communication apparatus for mutual communication,

when the communication apparatus is an authenticator communication apparatus that performs authentication,

the communication apparatus comprising:

a transmitting section that transmits challenge data to authenticate an authenticatee communication apparatus that is subject to authentication to the authenticatee communication apparatus in a first time slot of time slots that are segmented periods of time in which the communication apparatus is able to use a single communication channel by time division; and

a receiving section that receives first response data for responding to the challenge data from the authenticatee communication apparatus in a time slot provided after the first time slot, and

when the communication apparatus is the authenticatee communication apparatus that is subject to authentication,

the communication apparatus comprising;

a receiving section that receives the challenge data to authenticate the authenticatee communication apparatus from the authenticator communication apparatus that performs authentication in the first time slot of the time slots that are segmented periods of time in which the communication apparatus is able to use a single communication channel by time division; and

a transmitting section that transmits the first response data for responding to the challenge data to the authenticator communication apparatus in a time slot after the first time slot.

4. (canceled)

6. (canceled)

7. A communication apparatus for mutual communication,

when the communication apparatus is an authenticator communication apparatus that performs authentication,

the communication apparatus comprising:

a transmitting section that transmits challenge data to authenticate an authenticatee communication apparatus that is subject to authentication to the authenticatee communication apparatus in a time slot that is a segmented period of time in which the communication apparatus is able to use a single communication channel by time division; and

a receiving section that receives first response data for responding to the challenge data from the authenticatee communication apparatus in a same time slot as the time slot in which the transmitting section transmits the challenge data, and

when the communication apparatus is the authenticatee communication apparatus that is subject to authentication,

the communication apparatus comprising;

a receiving section that receives the challenge data to authenticate the authenticatee communication apparatus from the authenticator communication apparatus that performs authentication in a time slot that is a segmented period of time in which the communication apparatus is able to use a single communication channel by time division; and

a transmitting section that transmits the first response data for responding to the challenge data to the authenticator communication apparatus in a same time slot as the time slot in which the receiving section receives the challenge data.

9. (canceled)

10. (canceled)

15. (canceled)

20. (canceled)

21. A plurality of communication apparatuses for mutual communication,

when the communication apparatus is an authenticator communication apparatus that performs authentication,

the communication apparatus comprising:

a transmitting section that transmits to an authenticatee communication apparatus that is subject to authentication challenge data to authenticate the authenticatee communication apparatus together with a value to inquire whether the value matches at least part of an identifier of the authenticatee communication apparatus; and

a receiving section that receives from the authenticatee communication apparatus response data for responding to the challenge data together with a response indicating that the value received from the authenticator communication apparatus matches at least part of the identifier of the authenticatee communication apparatus,

when the communication apparatus is an authenticatee communication apparatus that is subject to authentication,

the communication apparatus comprising;

a receiving section that receives from the authenticator communication apparatus that performs authentication challenge data to authenticate the authenticatee communication apparatus together with the value to inquire whether the value matches at least part of the identifier of the authenticatee communication apparatus; and

a transmitting section that transmits to the authenticator communication apparatus response data for responding to the challenge data together with a response indicating that the value received from the authenticator communication apparatus matches at least part of the identifier of the authenticatee communication apparatus.

22. A communication method comprising:

transmitting challenge data to authenticate a second communication apparatus to the second communication apparatus by a first communication apparatus, in a time slot that is a segmented period of time in which a communication apparatus is able to use a single communication channel by time division, in a challenge data transmitting process;

transmitting response data for responding to the challenge data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits first challenge data to the second communication apparatus, in a response data transmitting process; and

authenticating the second communication apparatus by the first communication apparatus by using at least part of the challenge data transmitted to the second communication apparatus and at least part of the response data received from the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in an authenticating process.

23. The communication method of claim 22, wherein the first challenge data includes one of:

a set of a first encrypted random number obtained by encrypting a random number of the first communication apparatus, and a first encrypted identifier obtained by encrypting an identifier of the first communication apparatus, by using the first encrypted random number, and a set of a first decrypted random number obtained by decrypting the random number of the first communication apparatus, and a first decrypted identifier obtained by decrypting the identifier of the first communication apparatus by using the first decrypted random number, and

wherein first response data includes one of;

a set of a second decrypted random number obtained by further decrypting the random number of the first communication apparatus obtained by decrypting the first encrypted random number included in the first challenge data, and a decrypted identifier obtained by decrypting an identifier of the second communication apparatus by using the second decrypted random number, and

a set of a second encrypted random number obtained by further encrypting the random number of the first communication apparatus obtained by encrypting the first decrypted random number included in the first challenge data, and an encrypted identifier obtained by encrypting the identifier of the second communication apparatus by using the second encrypted random number.

24. A communication method comprising:

transmitting first challenge data to authenticate a second communication apparatus to the second communication apparatus by a first communication apparatus, in a time slot that is a segmented period of time in which a communication apparatus is able to use a single communication channel by time division, in a first challenge data transmitting process;

transmitting first response data for responding to the first challenge data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first response data transmitting process;

authenticating the second communication apparatus by the first communication apparatus by using at least part of the first challenge data transmitted to the second communication apparatus and at least part of the first response data received from the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first authenticating process;

transmitting second challenge data to authenticate the first communication apparatus to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second challenge data transmitting process;

transmitting second response data for responding to the second challenge data to the second communication apparatus by the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second response data transmitting process;

authenticating the first communication apparatus by the second communication apparatus by using at least part of the second challenge data transmitted to the first communication apparatus and at least part of the second response data received from the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second authenticating process; and

transmitting third response data for responding to the second response data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a third response data transmitting process.

28. The communication method of claim 24,

wherein the first challenge data includes one of:

a set of a first encrypted random number obtained by encrypting a random number of the first communication apparatus, and a first encrypted identifier obtained by encrypting an identifier of the first communication apparatus by using the first encrypted random number, and a set of a first decrypted random number obtained by decrypting the random number of the first communication apparatus, and a first decrypted identifier obtained by decrypting the identifier of the first communication apparatus by using the first decrypted random number,

wherein the first response data includes one of;

a set of a second decrypted random number obtained by decrypting a random number of the second communication apparatus, and a third decrypted random number obtained by further decrypting the random number of the first communication apparatus obtained by decrypting the first encrypted random number included in the first challenge data by using the second decrypted random number, and

a set of a second encrypted random number obtained by encrypting the random number of the second communication apparatus, and a third encrypted random number obtained by further encrypting the random number of the first communication apparatus obtained by encrypting the first decrypted random number included in the first challenge data by using the second encrypted random number,

wherein the second response data includes one of;

a set of the random number of the second communication apparatus obtained by decrypting the second encrypted random number included in the first response data, and a fourth decrypted random number obtained by further decrypting the random number of the second communication apparatus, and

a set of the random number of the second communication apparatus obtained by encrypting the second decrypted random number included in the first response data, and a fourth encrypted random number obtained by further encrypting the random number of the second communication apparatus, and

wherein the third response data includes one of;

a second encrypted identifier obtained by encrypting the identifier of the second communication apparatus by using the first encrypted random number, and

a second decrypted identifier obtained by decrypting the identifier of the second communication apparatus by using the first decrypted random number.

25. A communication method comprising:

transmitting first challenge data to authenticate a second communication apparatus to the second communication apparatus by a first communication apparatus, in a time slot that is a segmented period of time in which a communication apparatus is able to use a single communication channel by time division, in a first challenge data transmitting process;

transmitting second challenge data to authenticate the first communication apparatus and first response data for responding to the first challenge data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first response data transmitting process;

authenticating the second communication apparatus by the first communication apparatus by using at least part of the first challenge data transmitted to the second communication apparatus and at least part of the first response data received from the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first authenticating process;

transmitting second response data for responding to the second challenge data to the second communication apparatus by the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second response data transmitting process;

authenticating the first communication apparatus by the second communication apparatus by using at least part of the second challenge data transmitted to the first communication apparatus and at least part of the second response data received from the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second authenticating process; and

transmitting third response data for responding to the second response data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a third response data transmitting process.

26. A communication method comprising:

transmitting first challenge data to authenticate the second communication apparatus to a second communication apparatus by a first communication apparatus, in a time slot that is a segmented period of time in which a communication apparatus is able to use a single communication channel by time division, in a first challenge data transmitting process;

transmitting first response data for responding to the first challenge data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first response data transmitting process; and

authenticating the second communication apparatus by the first communication apparatus by using at least part of the first challenge data transmitted to the second communication apparatus and at least part of the first response data received from the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first authenticating process;

reporting to the second communication apparatus by the first communication apparatus that authenticity of the second communication apparatus is confirmed, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, when authenticity of the second communication apparatus is confirmed in the first authenticating process, in a reporting process;

transmitting the second challenge data to authenticate the first communication apparatus to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second challenge data transmitting process;

transmitting the second response data for responding to the second challenge data to the second communication apparatus by the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second response data transmitting process;

authenticating the first communication apparatus by the second communication apparatus by using at least part of the second challenge data transmitted to the first communication apparatus and at least part of the second response data received from the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second authenticating process; and

transmitting the third response data for responding to the second response data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a third response data transmitting process.

27. A communication method comprising:

transmitting first challenge data to authenticate a second communication apparatus to the second communication apparatus by a first communication apparatus, in a time slot that is a segmented period of time in which a communication apparatus is able to use a single communication channel by time division, in a first challenge data transmitting process;

transmitting first response data for responding to the first challenge data and second challenge data to authenticate the first communication apparatus to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first response data transmitting process;

authenticating the second communication apparatus by the first communication apparatus by using at least part of the first challenge data transmitted to the second communication apparatus and at least part of the first response data received from the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a first authenticating process;

reporting to the second communication apparatus by the first communication apparatus that authenticity of the second communication apparatus is confirmed, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, when the authenticity of the second communication apparatus is confirmed in the first authenticating process, in a reporting process;

transmitting the second response data for responding to the second challenge data to the second communication apparatus by the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a second response data transmitting process;

authenticating the first communication apparatus by the second communication apparatus by using at least part of the second challenge data transmitted to the first communication apparatus and at least part of the second response data received from the first communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data lo the second communication apparatus, in a second authenticating process; and

transmitting third response data for responding to the second response data to the first communication apparatus by the second communication apparatus, in a time slot after the time slot in which the first communication apparatus transmits the first challenge data to the second communication apparatus, in a third response data transmitting process.