CN103491540A - Wireless local area network two-way access authentication system and method based on identity certificates - Google Patents

Abstract

The invention discloses a wireless local area network two-way access authentication system and method based on identity certificates. The wireless local area network two-way access authentication system comprises access routers arranged in a safety area and further comprises an identity certificate management server and an authentication server. The identity certificate management server is used for managing the identity certificates of entities in the safety area, namely, issuing the identity certificates and maintaining the identity certificates. The authentication server is used for authenticating access certification application of mobile subscribers and completing shared key negotiation with the mobile subscribers. The access routers are used for controlling whether the mobile subscribers have access to the wireless local area network or not according to the authentication result fed back from the authentication server and receiving and forwarding authentication information between the mobile subscribers and the authentication server. According to the wireless local area network two-way access authentication system and method, in an autonomous security domain, two-way access authentication and secret key negotiation between the mobile subscribers and the accessed network can be achieved, efficient access authentication conducted when the mobile subscribers switch between the different access routers is supported, and the access authentication efficiency is improved.

Description

System and method for two-way access authentication of wireless local area network based on identity credential

technical field

The invention belongs to the field of wireless network security, and in particular relates to a two-way access authentication system and method for a wireless local area network based on identity certificates.

Background technique

With the rapid development of computer networks and mobile communication technologies, a large number of mobile devices have emerged, and people's demand for ubiquitous network access is becoming more and more urgent. As the extension and extension of the Internet, IEEE802.11 Wireless Local Area Network (WLAN) has become the best solution for the "last mile" access field due to its advantages of flexible deployment, heterogeneous compatibility, low cost, and rich bandwidth.

However, with the widespread deployment of WLAN, its security issues began to emerge. The next-generation wireless communication system requires WLAN to provide users with efficient and secure access services in an open environment, and access security is the key to ensuring WLAN security. When a mobile user accesses a WLAN, the access network needs to authenticate the identity of the mobile user to prevent illegal use of network resources. On the other hand, the mobile user needs to authenticate to access the network to obtain reliable access services. Two-way authentication between the visiting network and mobile users is the basis for secure WLAN access.

Existing solutions for WLAN secure access mainly include: a centralized access authentication method based on the 802.11i framework, a distributed access authentication method based on the PKI system, and an access authentication method based on an identity password system. (1) In the centralized authentication method based on 802.11i, when a mobile user accesses the access network, he first submits an authentication request to the access router, and the access router forwards the authentication request to the central authentication server, and the central authentication server authenticates the mobile user identity and complete the key negotiation between the mobile user and the access router. The centralized authentication mode requires the authentication entity to exchange a large number of messages with the remote central authentication server, which reduces the efficiency of access authentication. (2) In the PKI-based distributed access authentication method, the digital certificate authority (Certificate Authority, CA) issues X.509 digital certificates for the mobile user and the access router respectively. When the mobile user accesses the WLAN, the mobile user and the Access routers exchange and verify each other's digital certificates to achieve local two-way access authentication. However, the management and maintenance costs of digital certificates for mobile users and access routers limit the practicability of related schemes. (3) Identity-based cryptography (IBC) has emerged in recent years and has begun to be applied to the field of WLAN access authentication. Using identities as entity public keys can reduce the cost of digital certificate management and maintenance under the PKI system. The mobile user and the access router can realize two-way access authentication by verifying each other's identity-based signature. However, the private key of the entity is distributed by the Private Key Generator (PKG), which leads to a series of security issues such as key escrow and key transmission, making such schemes limited to applications in small-scale trusted networks.

It can be seen that the above-mentioned WLAN security mechanism has defects in authentication message exchange delay, digital certificate maintenance cost and applicability, and more importantly, when a mobile user switches between different access routers accessing the network, the complete access authentication process requires Re-execution further reduces the efficiency of access authentication.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a system and method for two-way access authentication of a wireless local area network based on identity certificates.

Technical scheme of the present invention is:

A two-way authentication system for wireless local area network access based on identity certificates, including an access router, which is set in a security domain, and also includes an identity certificate management server and an authentication server;

The identity certificate management server is used to manage the identity certificates of entities in the security domain, including issuing identity certificates and maintaining identity certificates; the identity certificates include issuer identity, issuer public key, user identity, user public key, user identity Valid period of certificate and identity certificate; entities in the security domain include: mobile users and access routers;

The authentication server is used to verify the mobile user's access authentication application and complete the shared key negotiation with the mobile user;

The access router is used to control whether the mobile user accesses the wireless local area network according to the verification result returned by the authentication server, and at the same time, the access router receives and forwards the authentication message between the mobile user and the authentication server.

The method for carrying out the two-way access authentication of the wireless local area network by using the two-way access authentication system of the wireless local area network based on the identity credential comprises the following steps:

Step 1: The identity credential management server generates system public parameters according to the selected security parameters and publishes the system public parameters;

的单向哈希函数H2：

为1到q-1范围的正整数，q为身份凭证管理服务器选择的安全参数，身份凭证管理服务器的公钥；The system public parameters include cyclic group G1 and cyclic group G2, bilinear pair e, base points P and G on cyclic group G1, one-way hash function H1 from character set to cyclic group G1, cyclic group G2 to

The one-way hash function H2:

It is a positive integer ranging from 1 to q-1, q is the security parameter selected by the identity certificate management server, and the public key of the identity certificate management server;

Step 2: The identity credential management server reviews the identity of the entity and issues the identity credential to the entity;

由实体随机选择，实体的公钥PK_EN=SK_EN·P，即循环群G1上的基点P与实体的私钥SK_EN的乘积；Step 2.1: Before the entity applies for an identity certificate, generate the entity's public key and private key pair based on the system public parameters, where the entity's private key

Randomly selected by the entity, the entity's public key PK _EN = SK _EN · P, that is, the product of the base point P on the cyclic group G1 and the entity's private key SK _EN ;

Step 2.2: The entity sends the identity information and the entity's public key to the identity certificate management server, and applies for an identity certificate to the identity certificate management server;

The identity information is a network address identifier;

Step 2.3: After receiving the entity's identity certificate application, the identity certificate management server verifies the validity of the entity's identity information. If the identity information is legal, it generates an identity certificate and issues it to the entity, otherwise it does not issue the identity certificate to the entity;

The identity certificate includes issuer identity, issuer public key, user identity, user public key, user identity certificate and identity certificate validity period, wherein the user identity certificate is generated by a certificate-based signature algorithm CBS;

Step 2.4: After the entity receives the identity certificate, use the entity's private key and the entity identity certificate in the identity certificate to generate the entity's signature key;

Step 3: When the mobile user moves into the security domain and requests to access an access router, two-way access authentication is performed between the mobile user, the access router and the authentication server;

Step 3.1: The mobile user sends an identity credential presentation message to the access router, and the access router forwards the message to the authentication server;

Step 3.1.1: The mobile user sends a router request message to find an access router in the current security domain;

Step 3.1.2: The access router performs access authentication after receiving the router request message sent by the mobile user;

Step 3.1.3: The access router sends a router response message to the mobile user, requesting the identity certificate of the mobile user;

Step 3.1.4: The mobile user sends an identity credential presentation message to the access router, which contains the mobile user's identity credential, the current timestamp, the key negotiation parameters of the mobile user, and uses the CBS algorithm to verify the identity credential based on the mobile user's signature key. Show the CBS signature result of the message;

The key negotiation parameter of the mobile user is the product of the public key of the mobile user and a random number;

Step 3.1.5: After the access router receives the mobile user's identity certificate presentation message, it forwards the message to the authentication server; Step 3.2: After the authentication server receives the mobile user's identity certificate presentation message, it checks the mobile user's identity certificate Verification: if the verification is successful, step 3.3 is performed; if the verification fails, the mobile user is denied access, and a verification failure message is sent to the access router;

Step 3.2.1: Verify the freshness of the time stamp in the mobile user's identity certificate presentation message to prevent replay attacks: if the time stamp is fresh, the authentication server verifies the validity period of the identity certificate, and executes step 3.2.2, otherwise the verification fails, Reject the mobile user's access, and send the verification failure message to the access router;

Step 3.2.2: If the identity certificate is within the validity period, the authentication server verifies the CBS signature result of the identity certificate presentation message, and executes step 3.2.3. If the identity certificate expires, a verification failure message is sent to the access router;

Step 3.2.3: The authentication server verifies the CBS signature result of the identity certificate presentation message according to the issuer public key and the user public key in the identity certificate: if the verification is passed, the authentication server confirms that the mobile user is a legal access user; If it fails, the mobile user is denied access, and a verification failure message is sent to the access router;

Step 3.3: The authentication server sends a message of successful verification of the mobile user's identity certificate to the mobile user;

Step 3.3.1: The authentication server sends a verification success message to the access router, and this message includes the key negotiation parameters of the authentication server;

The key negotiation parameter of the authentication server is the product of the public key of the authentication server and a random number;

Step 3.3.2: After the access router receives the verification success message sent by the authentication server, insert the identity certificate of the access router and the current timestamp into the message;

Step 3.3.3: The access router uses the CBS algorithm to perform CBS signature on the verification success message based on the signature key of the access router, and the access router sends the verification success message and the CBS signature result of the verification success message to the mobile user;

Step 3.4: After the mobile user receives the verification success message of the access router, verify the identity certificate of the access router: if the verification is successful, access the current access router and complete the two-way access authentication; if the verification fails, reject the access Enter the current access router;

Step 4: The authentication server and the mobile user perform shared key negotiation based on key negotiation parameters;

Step 4.1: The authentication server calculates the shared key between the authentication server and the mobile user based on the key negotiation parameters of the mobile user;

Step 4.2: The mobile user calculates the shared key between the mobile user and the authentication server based on the key negotiation parameters of the authentication server;

Step 5: When the mobile user continues to move in the security domain and accesses a new access router, use the shared key between the mobile user and the authentication server to perform handover access authentication;

Step 5.1: When the mobile user continues to move in the security domain and accesses a new access router, the mobile user sends an identity credential presentation message to the access router, and the access router forwards the message to the authentication server;

Step 5.1.1: The mobile user sends a router request message to find an access router in the current security domain;

Step 5.1.2: The access router performs access authentication after receiving the router request message sent by the mobile user;

Step 5.1.3: The access router sends a router response message to the mobile user, requesting the identity certificate of the mobile user;

Step 5.1.4: The mobile user sends an identity credential presentation message to the access router, which contains the mobile user's identity credential, the current time stamp, and the identity credential presentation message using the HMAC algorithm based on the shared key negotiated between the mobile user and the authentication server HMAC authentication result;

Step 5.1.5: After the access router receives the message of presenting the identity certificate of the mobile user, it forwards the message to the authentication server;

Step 5.2: After receiving the mobile user's identity certificate presentation message, the authentication server verifies the mobile user's identity certificate: if the verification is successful, then perform step 5.3; if the verification fails, reject the mobile user's access, and send a verification failure message sent to the access router;

Step 5.3: The authentication server sends a message of successful verification of the identity certificate of the mobile user to the mobile user;

Step 5.3.1: The authentication server sends a verification success message to the access router, which contains the encryption result of the authentication server using the public key of the access router to the shared key;

Step 5.3.2: After receiving the verification success message sent by the authentication server, the access router decrypts the shared key with the private key of the access router, and extracts the shared key;

Step 5.3.3: The access router inserts the identity certificate of the access router and the current time stamp in the authentication success message, and the access router uses the shared secret key to use the HMAC algorithm to perform HAMC authentication on the authentication success message, and the access router will verify the success message And the HMAC authentication result of the verification success message is sent to the mobile user;

Step 5.4: The mobile user uses the shared key negotiated with the authentication server to verify the legitimacy of the access router. If the access router is legal, the mobile user switches to the legal access router to complete the switch access authentication; If the router is illegal, the mobile user refuses to access the access router.

After the step 3.4 mobile user receives the verification success message of the access router, the identity certificate of the access router is verified, and the specific steps are as follows:

Step 3.4.1: The mobile user verifies the freshness of the time stamp in the received verification success message to prevent replay attacks: if the time stamp is fresh, verify the validity period of the access router’s identity certificate, and perform step 3.4.2; otherwise, verify Failed, deny access to the current access router;

Step 3.4.2: If the identity certificate is within the validity period, the mobile user verifies the CBS signature result of the verification success message, and executes step 3.4.3; if the identity certificate expires, then refuse to access the current access router;

Step 3.4.3: The mobile user verifies the CBS signature result of the verification success message according to the issuer's public key and the user's public key in the identity certificate: if the verification is passed, the mobile user confirms access to the legal access router and completes the two-way access Incoming authentication; if the authentication fails, the mobile user refuses to access the current access router.

The step 4.1 authentication server calculates the shared key between the authentication server and the mobile user based on the mobile user key negotiation parameters, and the specific steps are as follows:

Step 4.1.1: The authentication server takes the mobile user key negotiation parameters and the product of the base point G on the cyclic group G1 and the private key of the authentication server as input, and uses bilinear pairing e to calculate the shared key value of the authentication server;

Step 4.1.2: The authentication server uses the value of the authentication server's shared key as input, and uses the one-way hash function H2 to calculate its shared key with the mobile user.

The step 4.2 mobile user calculates the shared key between the mobile user and the authentication server based on the authentication server key negotiation parameters, and the specific steps are as follows:

Step 4.2.1: The mobile user takes the key negotiation parameters of the authentication server and the product of the base point G on the cyclic group G1 and the private key of the mobile user as input, and calculates the shared key value of the mobile user by using bilinear pairing e;

Step 4.2.2: The mobile user takes the mobile user's shared key value as input, and uses the one-way hash function H2 to calculate its shared key with the authentication server.

After the step 5.2 authentication server receives the mobile user's identity certificate to show the message, the mobile user's identity certificate is verified, and the specific steps are as follows:

Step 5.2.1: Verify the freshness of the time stamp in the mobile user's identity certificate presentation message to prevent replay attacks: if the time stamp is fresh, the authentication server verifies the validity period of the identity certificate, and executes step 5.2.2, otherwise the verification fails and rejects The mobile user accesses, and sends an authentication failure message to the access router;

Step 5.2.2: If the identity certificate is within the validity period, the authentication server verifies the HMAC authentication result of the identity certificate presentation message, and executes step 5.2.3. If the identity certificate expires, send a verification failure message to the access router;

Step 5.2.3: The authentication server verifies the HMAC authentication result of the identity credential presentation message according to the shared key negotiated with the mobile user: if the verification is passed, the authentication server confirms that the mobile user is a legitimate access user; if the verification fails, then Deny the access of the mobile user, and send an authentication failure message to the access router.

In step 5.4, the mobile user utilizes the shared key negotiated with the authentication server to verify the legitimacy of the access router, and the specific steps are as follows:

Step 5.4.1: The mobile user verifies the freshness of the time stamp in the received verification success message to prevent replay attacks: if the time stamp is fresh, verify the validity period of the identity certificate of the access router, and perform step 5.4.2; otherwise, verify Failed, deny access to the current access router;

Step 5.4.2: If the identity certificate is within the validity period, the mobile user verifies the HMAC authentication result of the verification success message, and executes step 5.4.3; if the identity certificate expires, refuse to access the current access router;

Step 5.4.3: The mobile user verifies the HMAC authentication result of the verification success message according to the shared key negotiated with the authentication server: if the verification is passed, the mobile user confirms access to the legal access router, and completes the handover access authentication; If the verification fails, the mobile user refuses to access the current access router.

Beneficial effect:

The system and method of the present invention can not only realize the two-way access authentication and key negotiation between the mobile user and the access network in an autonomous security domain, but also support the efficient access authentication of the mobile user when switching between different access routers, and improve the improved access authentication efficiency.

Description of drawings

Fig. 1 is the schematic diagram of the two-way access authentication system of the wireless local area network based on identity credential according to the specific embodiment of the present invention;

Fig. 2 is a flow chart of verifying the identity of an entity and issuing an identity certificate for the entity in a specific embodiment of the present invention;

Fig. 3 is a schematic diagram of the process of sending an identity credential presentation message from a mobile user to an authentication server according to a specific embodiment of the present invention;

Fig. 4 is the flow chart of the mobile user authentication by the authentication server according to the specific embodiment of the present invention;

FIG. 5 is a schematic diagram of a process in which the authentication server sends a verification success message to a mobile user according to a specific embodiment of the present invention;

Fig. 6 is the flow chart of the mobile user's authentication to the access router in the specific embodiment of the present invention;

FIG. 7 is a schematic diagram of a handover authentication process according to a specific embodiment of the present invention;

Fig. 8 is a flow chart of system module communication in a specific embodiment of the present invention;

FIG. 9 is a flowchart of a method for two-way access authentication of a wireless local area network according to a specific embodiment of the present invention.

Detailed ways

The specific implementation manners of the present invention will be described in detail below in conjunction with the accompanying drawings.

In this embodiment, the system and method for two-way access authentication of a wireless local area network based on an identity credential are applied to an access authentication link of a wireless local area network. The mature 802.11i authentication framework is used in the implementation process. For the bearer of authentication messages, the EAP protocol is used between the mobile user and the access router, and the RADIUS protocol is used between the access router and the authentication server.

As shown in Figure 1, the two-way access authentication system for WLAN based on identity credentials includes several access routers (including AR1 and AR2), set in an autonomous security domain, and also includes an identity credential management server (ICM) and an authentication Server (AS);

The identity credential management server is used to manage the identity credentials (Identity Credential, IC) of entities (access router AR and mobile user MN) in the security domain, including issuing identity credentials and maintaining identity credentials;

The identity certificate is an important basis in the two-way access authentication process, which is fundamentally different from the X.509 digital certificate under the PKI system. The X.509 digital certificate mainly realizes the binding of the user identity information and the held public key, and the identity certificate in this embodiment includes the issuer identity, the issuer public key, the user identity, the user public key, the user identity certificate and the validity period of the identity certificate ;

The authentication server is used to verify the mobile user's access authentication application and complete the shared key negotiation with the mobile user;

The access router is used to control whether the mobile user is allowed to access the WLAN according to the verification result returned by the authentication server, and at the same time, the access router receives and forwards the authentication message between the mobile user and the authentication server.

For the convenience of subsequent description, the identification and description shown in Table 1 are given.

Table 1 Identification and description

The method for carrying out the two-way access authentication of the wireless local area network by using the two-way access authentication system of the wireless local area network based on the identity certificate, as shown in Figure 9, includes the following steps:

Step 1: The identity credential management server ICM generates system public parameters according to the selected security parameters and publishes the system public parameters;

As a trusted third party in the security domain, ICM generates and publishes system public parameters;

的单向哈希函数H2(H1:{0,1}^*→G1，为1到q-1范围的正整数，q为身份凭证管理服务器选择的安全参数)，身份凭证管理服务器的公钥PK_ICM=SK_ICM·P，身份凭证管理服务器私钥

由身份凭证管理服务器随机选择；System public parameters {G1, G2, e, P, G, H1, H2, PK _ICM }, including cyclic group G1 and cyclic group G2, bilinear pair e, base points P and G on cyclic group G1, character set to The one-way hash function H1 of the cyclic group G1, the cyclic group G2 to

The one-way hash function H2(H1:{0,1} ^* →G1, is a positive integer ranging from 1 to q-1, q is the security parameter selected by the identity certificate management server), the public key of the identity certificate management server PK _ICM = SK _ICM P, the private key of the identity certificate management server

Randomly selected by the identity certificate management server;

Step 2: The identity credential management server reviews the identity of the entity and issues the identity credential to the entity, as shown in Figure 2;

由实体随机选择，实体的公钥PK_EN=SK_EN·P，即循环群G1上的基点P与实体的私钥SK_EN的乘积；Step 2.1: Before the entity applies for an identity certificate, generate the entity's public key and private key pair based on the system public parameters, where the entity's private key

Randomly selected by the entity, the entity's public key PK _EN = SK _EN · P, that is, the product of the base point P on the cyclic group G1 and the entity's private key SK _EN ;

Step 2.2: The entity sends the identity information and the entity's public key to the identity certificate management server, and applies for an identity certificate to the identity certificate management server;

The identity information is a network address identifier, such as EntityDomain;

Step 2.3: After receiving the entity's identity certificate application, the identity certificate management server verifies the validity of the entity's identity information. If the identity information is legal, it generates an identity certificate and issues it to the entity, otherwise it does not issue the identity certificate to the entity;

The identity certificate includes the identity of the issuer, the public key of the issuer, the identity of the user, the public key of the user, the user identity certificate and the validity period of the identity certificate, wherein the user identity certificate is generated by the certificate-based signature algorithm CBS;

The entity identity certificate in the identity certificate is:

Cert _EN =SK _ICM P _EN ，P _EN =H ₁ (PK _ICM ||PK _EN ||ID _EN )∈G1.

Step 2.4: After the entity receives the identity certificate, use the entity's private key and the entity identity certificate in the identity certificate to generate the entity's signature key;

The entity's signing key is:

SignKey _EN =Cert _EN +SK _EN P _EN .

Step 3: When the mobile user moves into the security domain and requests to access an access router AR, two-way access authentication is performed between the mobile user MN, the access router AR and the authentication server AS;

Step 3.1: The mobile user sends an identity credential presentation message to the access router, and the access router AR forwards the message to the authentication server, as shown in Figure 3;

Step 3.1.1: The mobile user sends a router request message to find an access router in the current security domain;

The MN sends a data packet (EAP-Start) using the EAP protocol to find an AR in the security domain, and only the EAP contains the necessary fields of the frame in the sent EAP multicast frame;

Step 3.1.2: The access router performs access authentication after receiving the router request message sent by the mobile user;

Step 3.1.3: The access router sends a router response message to the mobile user, requesting the identity certificate of the mobile user;

After receiving the EAP-Start of the MN, the AR sends an EAP data packet (EAP-Request-Credential) to the MN, requesting the identity credential information of the MN;

Step 3.1.4: The mobile user sends an identity credential post message to the access router, which includes the mobile user's identity credential, the current timestamp (Ts1), the key negotiation parameters of the mobile user and the use of CBS based on the signature key of the mobile user. The CBS signature result σ of the message displayed by the algorithm to the identity certificate;

The mobile user sends an identity credential display message to the access router through the EAP data packet (EAP-Response);

The key negotiation parameter of the mobile user is the product of the public key of the mobile user and the random number,

Based on the signature key of the mobile user, use the CBS algorithm to sign the CBS signature result of the post-display message of the identity credential σ=(U,V), U=r·P _MN ,h=H2(m,U),V=(r+h )·SignKey _MN , m is the post-display message of the identity certificate;

Step 3.1.5: After the access router receives the post-disclosure message of the mobile user's identity certificate, it forwards the message to the authentication server;

After receiving the MN's identity credential presentation message, the AR obtains the corresponding data from the data part of the EAP protocol, repackages it into the RADIUS protocol, and forwards the identity credential presentation message to the AS through a RADIUS packet (RADIUS-Access-Request);

Step 3.2: After receiving the mobile user's identity certificate presentation message, the authentication server verifies the mobile user's identity certificate as shown in Figure 4: if the verification is successful, then perform step 3.3; if the verification fails, reject the mobile user's access , and send an authentication failure message to the access router;

Step 3.2.1: Verify the freshness of the time stamp Ts1 in the mobile user's identity certificate presentation message to prevent replay attacks: if the time stamp Ts1 is fresh, the authentication server verifies the validity period of the identity certificate, and executes step 3.2.2, otherwise verifies Fail, deny the mobile user access, and send the verification failure message to the access router;

Step 3.2.2: If the identity certificate is within the validity period, the authentication server verifies the CBS signature result of the identity certificate presentation message, and executes step 3.2.3. If the identity certificate expires, a verification failure message is sent to the access router;

Step 3.2.3: The authentication server verifies the CBS signature result of the identity certificate presentation message according to the issuer public key and the user public key in the identity certificate: if the verification is passed, the authentication server confirms that the mobile user is a legal access user; If it fails, the mobile user is denied access, and a verification failure message is sent to the access router;

The authentication server verifies the CBS signature result σ of the identity credential presentation message as follows:

e(PK _ICM +PK _MN ,U+hP _MN )=? e(P,V).

Step 3.3: The authentication server sends a message of successful verification of the mobile user's identity certificate to the mobile user, as shown in Figure 5;

Step 3.3.1: The authentication server sends a verification success message to the access router, and this message includes the key negotiation parameters of the authentication server;

The authentication server sends an authentication success message to the access router through a RADIUS packet (RADIUS-Access-Success);

The key negotiation parameter of the authentication server is the product of the public key of the authentication server and a random number,

Step 3.3.2: After the access router receives the verification success message sent by the authentication server, insert the identity certificate of the access router and the current timestamp (Ts2) into the message;

After the access router receives the verification success message from the authentication server, it obtains the corresponding data from the data part in the RADIUS protocol, inserts the identity certificate and the current timestamp (Ts2) of the access router, and then re-encapsulates it into the EAP protocol;

Step 3.3.3: The access router uses the CBS algorithm to perform CBS signature on the verification success message based on the signature key of the access router, and the access router sends the verification success message and the CBS signature result of the verification success message to the mobile user;

Based on the signature key of the access router, use the CBS algorithm to verify the CBS signature result of the successful message σ′=(U′,V′), U′=r′·P _AR ,h′=H2(m′,U′) , V′=(r′+h′)·SignKey _AR , where, m' is the verification success message;

The access router forwards the verification success message and the CBS signature result to the mobile user through the EAP packet (EAP-Success);

Step 3.4: As shown in Figure 6, after the mobile user receives the verification success message of the access router, he verifies the identity certificate of the access router: if the verification is successful, he accesses the current access router and completes two-way access authentication; if If the verification fails, the access to the current access router is rejected;

After the mobile user receives the verification success message of the access router, the identity certificate of the access router is verified, and the specific steps are as follows:

Step 3.4.1: The mobile user verifies the freshness of the time stamp (Ts2) in the received verification success message to prevent replay attacks: if the time stamp (Ts2) is fresh, then verify the validity period of the access router identity certificate, and perform the steps 3.4.2; Otherwise, the verification fails and the access to the current access router is rejected;

Step 3.4.2: If the identity certificate is within the validity period, the mobile user verifies the CBS signature result of the verification success message, and executes step 3.4.3; if the identity certificate expires, then refuse to access the current access router;

Step 3.4.3: The mobile user verifies the CBS signature result of the verification success message according to the issuer's public key and the user's public key in the identity certificate: if the verification is passed, the mobile user confirms access to the legal access router and completes the two-way access Incoming authentication; if the authentication fails, the mobile user refuses to access the current access router.

The mobile user performs the following verification on the CBS signature result σ' of the successful verification message:

e(PK _ICM +PK _AR , U′+h′P _AR )=? e(P,V').

Step 4: The authentication server and the mobile user perform shared key negotiation based on key negotiation parameters;

Step 4.1: The authentication server calculates the shared key between the authentication server and the mobile user based on the key negotiation parameters of the mobile user;

Step 4.1.1: The authentication server takes the mobile user key negotiation parameters and the product of the base point G on the cyclic group G1 and the private key of the authentication server as input, and uses bilinear pairing e to calculate the shared key value of the authentication server;

ShareKey_Value _AS-MN = e(b T _a , SK _AS G),

Among them, ShareKey_Value _AS-MN is the shared key value between AS and MN, and b is the random selection parameter of AS;

Step 4.1.2: The authentication server takes the value of the shared key of the authentication server as input, and uses the one-way hash function H2 to calculate the shared key of the authentication server and the mobile user.

ShareKey _AS-MN =H2(ShareKey_Value _AS-MN ).

Among them, ShareKey _AS-MN is the shared key between AS and MN;

Step 4.2: The mobile user calculates the shared key between the mobile user and the authentication server based on the key negotiation parameters of the authentication server;

Step 4.2.1: The mobile user takes the key negotiation parameters of the authentication server and the product of the base point G on the cyclic group G1 and the private key of the mobile user as input, and calculates the shared key value of the mobile user by using bilinear pairing e;

ShareKey_Value _MN-AS = e(a T _b , SK _MN G),

Among them, ShareKey_Value _MN-AS is the shared key value between MN and AS, and a is the parameter randomly selected by MN;

Step 4.2.2: The mobile user takes the mobile user's shared key value as input, and uses the one-way hash function H2 to calculate its shared key with the authentication server.

ShareKey _MN-AS =H2(ShareKey_Value _MN-AS )

Among them, ShareKey _MN-AS is the shared key between MN and AS;

Step 5: As shown in Figure 7, when the mobile user continues to move in the security domain and accesses a new access router, use the shared key between the mobile user and the authentication server to perform handover access authentication;

Step 5.1: When the mobile user continues to move in the security domain and accesses a new access router AR', the mobile user sends an identity credential presentation message to the access router, and the access router forwards the message to the authentication server;

Step 5.1.1: The mobile user sends a router request message to find an access router in the current security domain;

Step 5.1.2: The access router performs access authentication after receiving the router request message sent by the mobile user;

Step 5.1.3: The access router sends a router response message to the mobile user, requesting the identity certificate of the mobile user;

Step 5.1.4: The mobile user sends an identity credential presentation message to the access router, which contains the mobile user's identity credential, the current time stamp Ts3 and uses the HMAC algorithm to present the identity credential based on the shared key negotiated between the mobile user and the authentication server HMAC authentication result of the message

的生成过程如下：

The generation process is as follows:

$<span\; class="notranslate">\; \&PartialD;</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; HMAC</span>}}_{\mathrm{<span\; class="notranslate">\; MN</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Cred</span>}}_{\mathrm{<span\; class="notranslate">\; MN</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; Ts</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; S</span>}{\mathrm{<span\; class="notranslate">\; hareKey</span>}}_{\mathrm{<span\; class="notranslate">\; MN</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; AS</span>}}<span\; class="notranslate">\; )</span>$

Step 5.1.5: After the access router receives the message of presenting the identity certificate of the mobile user, it forwards the message to the authentication server;

After receiving the MN's identity credential presentation message, the AR obtains the corresponding data from the data part of the EAP protocol, repackages it into the RADIUS protocol, and forwards the identity credential presentation message to the AS through a RADIUS packet (RADIUS-Access-Request);

Step 5.2: After receiving the mobile user's identity certificate presentation message, the authentication server verifies the mobile user's identity certificate: if the verification is successful, then perform step 5.3; if the verification fails, reject the mobile user's access, and send a verification failure message sent to the access router;

After the authentication server receives the mobile user's identity certificate presentation message, it verifies the mobile user's identity certificate, and the specific steps are as follows:

Step 5.2.1: Verify the freshness of the time stamp Ts3 in the mobile user’s identity certificate presentation message to prevent replay attacks: if the time stamp Ts3 is fresh, the authentication server verifies the validity period of the identity certificate, and execute step 5.2.2, otherwise the verification fails , rejecting the access of the mobile user, and sending an authentication failure message to the access router;

Step 5.2.2: If the identity certificate is within the validity period, the authentication server verifies the HMAC authentication result of the identity certificate presentation message, and executes step 5.2.3. If the identity certificate expires, send a verification failure message to the access router;

Step 5.2.3: The authentication server verifies the HMAC authentication result of the identity credential presentation message according to the shared key negotiated with the mobile user: if the verification is passed, the authentication server confirms that the mobile user is a legitimate access user; if the verification fails, then Deny the access of the mobile user, and send an authentication failure message to the access router.

进行如下验证：The HMAC authentication result of the message presented by the authentication server to the identity certificate

Verify as follows:

Step 5.3: The authentication server sends a message of successful verification of the identity certificate of the mobile user to the mobile user;

Step 5.3.1: The authentication server sends a verification success message to the access router, which contains the encryption result of the authentication server using the public key of the access router to the shared key;

Step 5.3.2: After receiving the verification success message sent by the authentication server, the access router decrypts the shared key with the private key of the access router, and extracts the shared key;

Step 5.3.3: The access router inserts the identity certificate of the access router and the current time stamp in the authentication success message, and the access router uses the shared secret key to use the HMAC algorithm to perform HAMC authentication on the authentication success message, and the access router will verify the success message And the HMAC authentication result of the verification success message is sent to the mobile user;

如下：HMAC authentication result for successful authentication message

as follows:

${<span\; class="notranslate">\; \&PartialD;</span>}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; HMAC</span>}}_{\mathrm{<span\; class="notranslate">\; AS</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Cred</span>}}_{\mathrm{<span\; class="notranslate">\; AS</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; Ts</span>}\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; S</span>}{\mathrm{<span\; class="notranslate">\; hareKey</span>}}_{\mathrm{<span\; class="notranslate">\; AS</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; MN</span>}}<span\; class="notranslate">\; )</span>$

Step 5.4: The mobile user uses the shared key negotiated with the authentication server to verify the legitimacy of the access router. If the access router is legal, the mobile user switches to the legal access router to complete the switch access authentication; If the router is illegal, the mobile user refuses to access the access router.

The mobile user uses the shared key negotiated with the authentication server to verify the legitimacy of the access router, and the specific steps are as follows:

Step 5.4.1: The mobile user verifies the freshness of the time stamp Ts4 in the received verification success message to prevent replay attacks: if the time stamp Ts4 is fresh, verify the validity period of the access router identity certificate, and perform step 5.4.2; Otherwise, the verification fails and the access to the current access router is rejected;

Step 5.4.2: If the identity certificate is within the validity period, the mobile user verifies the HMAC authentication result of the verification success message, and executes step 5.4.3; if the identity certificate expires, refuse to access the current access router;

Step 5.4.3: The mobile user verifies the HMAC authentication result of the verification success message according to the shared key negotiated with the authentication server: if the verification is passed, the mobile user confirms access to the legal access router, and completes the handover access authentication; If the verification fails, the mobile user refuses to access the current access router.

进行如下验证：The mobile user's HMAC authentication result for the successful authentication message

Verify as follows:

Based on the above described process, the two-way access authentication system for WLAN based on identity credentials is designed and implemented. The system is developed on the Windows platform, the programming language is C++, the development tool is Visual Studio, the library function used is Winpcap, and the network layer communication protocol is UDP.

The main functions of the MN module are: discovering AR, presenting credentials and verifying credentials. Design initialization class, demonstration class, verification class and encryption and decryption class in MN module. The initialization class mainly initializes the system, and then monitors the data of the network adapter; calls the demonstration class according to the received data to send the identity certificate presentation message; finally calls the verification class and the encryption and decryption class to perform two-way verification on the received verification success message. The MN module class design is shown in Table 2.

Table 2 Class design of MN module

The main functions of the AR module are: receive identity credential presentation message from MN and forward it to AS, receive verification success message from AS, decrypt shared key, HMAC authentication, and forward corresponding message to MN. Design the initialization class, data analysis and processing class and encryption and decryption class in the AR module. The initialization class is mainly responsible for system initialization and receiving data from MN and AS; after receiving the data, call the data analysis and processing class and the encryption and decryption class to analyze and process the received data, and perform protocol encapsulation on the corresponding data; finally in the authentication After completion, control the access of the MN. The AR module class design is shown in Table 3.

Table 3 Class design of AR module

The main functions of the AS module are: performing access authentication on the MN, and negotiating a shared key with the MN. Design the initialization class, data analysis and processing class, verification class, demonstration class and encryption and decryption class in the AS module. The initialization class is mainly responsible for system initialization and receiving data; the data analysis and processing class is responsible for analyzing and processing the received data; then call the verification class to verify the MN; after the verification is passed, call the demonstration class to return a verification success message to AR. AS module class design is shown in Table 4.

Table 4 Class design of AS module

Combining the above module and class design, the MN module, AR module and AS module involved in the access authentication can be programmed and implemented according to the flow shown in Figure 8 .

Claims (7)

1. A wireless local area network two-way access authentication system based on identity credentials, comprising an access router, arranged in a security domain, characterized in that: it also includes an identity credentials management server and an authentication server; The identity certificate management server is used to manage the identity certificates of entities in the security domain, including issuing identity certificates and maintaining identity certificates; the identity certificates include issuer identity, issuer public key, user identity, user public key, user identity Valid period of certificate and identity certificate; entities in the security domain include: mobile users and access routers; The authentication server is used to verify the mobile user's access authentication application and complete the shared key negotiation with the mobile user; The access router is used to control whether the mobile user accesses the wireless local area network according to the verification result returned by the authentication server, and at the same time, the access router receives and forwards the authentication message between the mobile user and the authentication server. 2. adopt the method for the two-way access authentication of wireless local area network based on the wireless local area network two-way access authentication system of claim 1, it is characterized in that: comprise the following steps: Step 1: The identity credential management server generates system public parameters according to the selected security parameters and publishes the system public parameters; The system public parameters include cyclic group G1 and cyclic group G2, bilinear pair e, base points P and G on cyclic group G1, one-way hash function H1 from character set to cyclic group G1, cyclic group G2 to

The one-way hash function H2:

It is a positive integer ranging from 1 to q-1, q is the security parameter selected by the identity certificate management server, and the public key of the identity certificate management server; Step 2: The identity credential management server reviews the identity of the entity and issues the identity credential to the entity; Step 2.1: Before the entity applies for an identity certificate, generate the entity's public key and private key pair based on the system public parameters, where the entity's private key

Randomly selected by the entity, the entity's public key PK _EN = SK _EN · P, that is, the product of the base point P on the cyclic group G1 and the entity's private key SK _EN ; Step 2.2: The entity sends the identity information and the entity's public key to the identity certificate management server, and applies for an identity certificate to the identity certificate management server; The identity information is a network address identifier; Step 2.3: After receiving the entity's identity certificate application, the identity certificate management server verifies the validity of the entity's identity information. If the identity information is legal, it generates an identity certificate and issues it to the entity, otherwise it does not issue the identity certificate to the entity; The identity certificate includes issuer identity, issuer public key, user identity, user public key, user identity certificate and identity certificate validity period, wherein the user identity certificate is generated by a certificate-based signature algorithm CBS; Step 2.4: After the entity receives the identity certificate, use the entity's private key and the entity identity certificate in the identity certificate to generate the entity's signature key; Step 3: When the mobile user moves into the security domain and requests to access an access router, two-way access authentication is performed between the mobile user, the access router and the authentication server; Step 3.1: The mobile user sends an identity credential presentation message to the access router, and the access router forwards the message to the authentication server; Step 3.1.1: The mobile user sends a router request message to find an access router in the current security domain; Step 3.1.2: The access router performs access authentication after receiving the router request message sent by the mobile user; Step 3.1.3: The access router sends a router response message to the mobile user, requesting the identity certificate of the mobile user; Step 3.1.4: The mobile user sends an identity credential presentation message to the access router, which contains the mobile user's identity credential, the current timestamp, the key negotiation parameters of the mobile user, and uses the CBS algorithm to verify the identity credential based on the mobile user's signature key. Show the CBS signature result of the message; The key negotiation parameter of the mobile user is the product of the public key of the mobile user and a random number; Step 3.1.5: After the access router receives the message of presenting the identity certificate of the mobile user, it forwards the message to the authentication server; Step 3.2: After receiving the mobile user's identity certificate presentation message, the authentication server verifies the mobile user's identity certificate: if the verification is successful, then perform step 3.3; if the verification fails, then reject the mobile user's access, and send a verification failure message sent to the access router; Step 3.2.1: Verify the freshness of the time stamp in the mobile user's identity certificate presentation message to prevent replay attacks: if the time stamp is fresh, the authentication server verifies the validity period of the identity certificate, and executes step 3.2.2, otherwise the verification fails, Reject the mobile user's access, and send the verification failure message to the access router; Step 3.2.2: If the identity credential is within the validity period, the authentication server verifies the CBS signature result of the identity credential presentation message, execute step 3.2.3, if the identity credential expires, send a verification failure message to the access router; Step 3.2.3: The authentication server verifies the CBS signature result of the identity certificate presentation message according to the issuer public key and the user public key in the identity certificate: if the verification is passed, the authentication server confirms that the mobile user is a legal access user; If it fails, the mobile user is denied access, and a verification failure message is sent to the access router; Step 3.3: The authentication server sends a message of successful verification of the mobile user's identity certificate to the mobile user; Step 3.3.1: The authentication server sends a verification success message to the access router, and this message includes the key negotiation parameters of the authentication server; The key negotiation parameter of the authentication server is the product of the public key of the authentication server and a random number; Step 3.3.2: After the access router receives the verification success message sent by the authentication server, insert the identity certificate of the access router and the current timestamp into the message; Step 3.3.3: The access router uses the CBS algorithm to perform CBS signature on the verification success message based on the signature key of the access router, and the access router sends the verification success message and the CBS signature result of the verification success message to the mobile user; Step 3.4: After the mobile user receives the verification success message of the access router, verify the identity certificate of the access router: if the verification is successful, access the current access router and complete the two-way access authentication; if the verification fails, reject the access Enter the current access router; Step 4: The authentication server and the mobile user perform shared key negotiation based on key negotiation parameters; Step 4.1: The authentication server calculates the shared key between the authentication server and the mobile user based on the key negotiation parameters of the mobile user; Step 4.2: The mobile user calculates the shared key between the mobile user and the authentication server based on the key negotiation parameters of the authentication server; Step 5: When the mobile user continues to move in the security domain and accesses a new access router, use the shared key between the mobile user and the authentication server to perform handover access authentication; Step 5.1: When the mobile user continues to move in the security domain and accesses a new access router, the mobile user sends an identity credential presentation message to the access router, and the access router forwards the message to the authentication server; Step 5.1.1: The mobile user sends a router request message to find an access router in the current security domain; Step 5.1.2: The access router performs access authentication after receiving the router request message sent by the mobile user; Step 5.1.3: The access router sends a router response message to the mobile user, requesting the identity certificate of the mobile user; Step 5.1.4: The mobile user sends an identity credential presentation message to the access router, which contains the mobile user's identity credential, the current timestamp, and uses the HMAC algorithm to present the identity credential based on the shared secret key negotiated between the mobile user and the authentication server. HMAC authentication result of the message; Step 5.1.5: After the access router receives the message of presenting the identity certificate of the mobile user, it forwards the message to the authentication server; Step 5.2: After receiving the mobile user's identity certificate presentation message, the authentication server verifies the mobile user's identity certificate: if the verification is successful, then perform step 5.3; if the verification fails, reject the mobile user's access, and send a verification failure message sent to the access router; Step 5.3: The authentication server sends a message of successful verification of the identity certificate of the mobile user to the mobile user; Step 5.3.1: The authentication server sends a verification success message to the access router, which contains the encryption result of the authentication server using the public key of the access router to the shared key; Step 5.3.2: After receiving the verification success message sent by the authentication server, the access router decrypts the shared key with the private key of the access router, and extracts the shared key; Step 5.3.3: The access router inserts the identity certificate of the access router and the current time stamp in the authentication success message, and the access router uses the shared secret key to use the HMAC algorithm to perform HAMC authentication on the authentication success message, and the access router will verify the success message And the HMAC authentication result of the verification success message is sent to the mobile user; Step 5.4: The mobile user uses the shared key negotiated with the authentication server to verify the legitimacy of the access router. If the access router is legal, the mobile user switches to the legal access router to complete the switch access authentication; If the router is illegal, the mobile user refuses to access the access router. 3. The two-way access authentication method for wireless local area network based on identity credentials according to claim 2, characterized in that: after the step 3.4 mobile user receives the verification success message of the access router, the identity credentials of the access router are checked. Verification, the specific steps are as follows: Step 3.4.1: The mobile user verifies the freshness of the time stamp in the received verification success message to prevent replay attacks: if the time stamp is fresh, verify the validity period of the access router’s identity certificate, and perform step 3.4.2; otherwise, verify Failed, deny access to the current access router; Step 3.4.2: If the identity certificate is within the validity period, the mobile user verifies the CBS signature result of the verification success message, and executes step 3.4.3; if the identity certificate expires, then refuse to access the current access router; Step 3.4.3: The mobile user verifies the CBS signature result of the verification success message according to the issuer's public key and the user's public key in the identity certificate: if the verification is passed, the mobile user confirms access to the legal access router and completes the two-way access Incoming authentication; if the authentication fails, the mobile user refuses to access the current access router. 4. The two-way access authentication method for wireless local area network based on identity credentials according to claim 2, characterized in that: said step 4.1 authentication server calculates the shared key between the authentication server and the mobile user based on the mobile user key negotiation parameters, Specific steps are as follows: Step 4.1.1: The authentication server takes the mobile user key negotiation parameters and the product of the base point G on the cyclic group G1 and the private key of the authentication server as input, and uses bilinear pairing e to calculate the shared key value of the authentication server; Step 4.1.2: The authentication server uses the value of the authentication server's shared key as input, and uses the one-way hash function H2 to calculate its shared key with the mobile user. 5. The two-way access authentication method for wireless local area network based on identity credentials according to claim 2, characterized in that: said step 4.2 mobile user calculates the shared key between the mobile user and the authentication server based on the authentication server key negotiation parameters, Specific steps are as follows: Step 4.2.1: The mobile user takes the key negotiation parameters of the authentication server and the product of the base point G on the cyclic group G1 and the private key of the mobile user as input, and calculates the shared key value of the mobile user by using bilinear pairing e; Step 4.2.2: The mobile user takes the mobile user's shared key value as input, and uses the one-way hash function H2 to calculate its shared key with the authentication server. 6. The two-way access authentication method for wireless local area network based on identity credentials according to claim 2, characterized in that: after said step 5.2 authentication server receives the identity credentials of the mobile user to show the message, the identity credentials of the mobile user are verified ,Specific steps are as follows: Step 5.2.1: Verify the freshness of the time stamp in the mobile user's identity certificate presentation message to prevent replay attacks: if the time stamp is fresh, the authentication server verifies the validity period of the identity certificate, and executes step 5.2.2, otherwise the verification fails and rejects The mobile user accesses, and sends an authentication failure message to the access router; Step 5.2.2: If the identity certificate is within the validity period, the authentication server verifies the HMAC authentication result of the identity certificate presentation message, and executes step 5.2.3. If the identity certificate expires, send a verification failure message to the access router; Step 5.2.3: The authentication server verifies the HMAC authentication result of the identity credential presentation message according to the shared key negotiated with the mobile user: if the verification is passed, the authentication server confirms that the mobile user is a legitimate access user; if the verification fails, then Deny the access of the mobile user, and send an authentication failure message to the access router. 7. The two-way access authentication method for wireless local area network based on identity credentials according to claim 2, characterized in that: said step 5.4 mobile user utilizes its shared key negotiated with the authentication server to verify the legitimacy of the access router, specifically Proceed as follows: Step 5.4.1: The mobile user verifies the freshness of the time stamp in the received verification success message to prevent replay attacks: if the time stamp is fresh, verify the validity period of the identity certificate of the access router, and perform step 5.4.2; otherwise, verify Failed, deny access to the current access router; Step 5.4.2: If the identity certificate is within the validity period, the mobile user verifies the HMAC authentication result of the verification success message, and executes step 5.4.3; if the identity certificate expires, refuse to access the current access router; Step 5.4.3: The mobile user verifies the HMAC authentication result of the verification success message according to the shared key negotiated with the authentication server: if the verification is passed, the mobile user confirms access to the legal access router, and completes the handover access authentication; If the verification fails, the mobile user refuses to access the current access router.

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