Network key management and session key updating method

FIELD OF THE INVENTION The present invention relates to a method for network key peopleagement and session key update, which can be specifically applied to wired networks, wireless local area networks (WLAN), and wireless metropolitan area networks ( Wpeople), Broadband Wireless Multimedia (BWM) network and other wireless networks. Background The security issues of wireless networks are far more important than wired Ethernet. The US IEEE has developed 802.11 and 802.16 series of standards to enhance the security of wireless local area networks and wireless metropolitan area networks, and provide secure access from mobile terminals to base stations. China also promulgated the national standard for wireless local area networks GB15629.11 in May 2003, usually It is called the WAPI protocol. Broadband wireless multimedia network integrates data communication and broadcast communication. It is a new wireless network architecture. It also needs to solve the problem of secure access and confidential communication. One of the key problems to solve the confidential communication is how to peopleage various keys in the system.

The IEEE802.11 standard uses the WEI protocol to achieve WLAN security. Its key peopleagement is very simple, that is, a shared key is peopleually set between the mobile terminal and the access point. The disadvantages are: there is no perfect key peopleagement scheme, which is not conducive to the expansion of the system, and the flexibility of the system is poor.

The WEP encryption protocol has serious security loopholes. The IEEE802. lli standard peopleages and derives keys through a four-way handshake protocol. Although it solves the security problems of WEP, it has the following shortcomings: (1) Key peopleagement cannot distinguish service levels. The key derivation is for certain terminals and access points, and different keys cannot be derived for different services to achieve service level division.

(2) The efficiency of multicast key negotiation is low. The access point needs to negotiate the multicast key with each of a group of mobile terminals separately.

(3) The Kuai efficiency of the multicast key is low. The process of the multicast key also needs to be merged with each mobile terminal separately, and the efficiency is often low.

(4) It is not possible to provide different multicast encryption keys for different services.

The Chinese national standard GB15629.il overcomes some of the shortcomings of WEP, but its key peopleagement protocol still has the same shortcomings as IEEE802. lli.

The Wpeople standard IEEE802.16 proposed by the US IEEE cannot prevent attackers from pretending to be a base station to deceive mobile terminals, and its key peopleagement is also insecure. The IEEE802.16 standard draws on the EEE802. lli standard to condense the S scheme, but its key peopleagement has the following shortcomings: The key peopleagement adopts the time synchronization method, and the state peopleagement is more complicated. The enabling and disabling of the new key depends on time judgment, and it is more complicated to maintain a synchronized clock in a distributed system. There are peopley system states and complicated peopleagement.

200610104679.4 Summary of the invention The purpose of the present invention is to provide a network connection secret bait peopleagement and session secret calcium update method, which solves the technical problems of low efficiency in the negotiation and update of multicast keys and complex system state peopleagement in the most advanced technology. .

The technical solution of the present invention is: A network unicast key peopleagement method, the special feature of which is that the implementation steps of the method include: (1) Constructing a key negotiation request group: during initial key negotiation, or mobile terminal When a key update is required or a session key update notification packet sent by the base station is received, the mobile terminal sends a key agreement request packet to the base station to activate the key agreement process; (2) Construct a key agreement response packet: (2.1) Base station After receiving the key agreement request from the mobile terminal, construct a key agreement response packet; (2.2) If the base station sends the key update notification packet first, the 0 base station checks the key update notification packet and the key agreement request packet. Whether the values of the corresponding fields are the same. If they are the same, construct the key agreement response packet; if they are not the same, discard the key agreement request packet without any processing; (2. 3) The base station sends a key agreement response packet to the mobile terminal, leading the unicast session encryption key and the integrity check key; (3) Constructing a key agreement confirmation packet: The mobile terminal receives the key agreement response from the base station Use the authorization key>AKID corresponding to the authorization key to decrypt the key encryption key derived from the authorization key to obtain the session key material TEKM, and use the random number selected by the base station and mobile terminal to derive the session encryption key and the integrity check secret Key to construct a key agreement confirmation group; the contents of the above-mentioned key update notification group include: the identity IDbs of the base station, the security association ID SAID, the authorization key ID AKID, the session key ID TEKID, and the message integrity check code MIC, where The session key identifier TEKID is used to identify the session key that needs to be updated, and the value of the message integrity check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to the AKID.

The content of the above-mentioned key agreement request packet includes: the identity of the mobile terminal %, the security association identifier SAID, the authorization key identifier AKΠΧ session key identifier TEKΠΧ mobile terminal selected by the mobile terminal, the message integrity check code MIC, where: The session key identifier TEKID is used to identify the session key that needs to be updated, and the value of the message integrity check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to the AKID; the content of the above key negotiation response packet Including: the identity of the mobile terminal and the identity security association of the base station "SAID, authorization key" UOD, know tongue key "UEKID, the mobile terminal with "Nms, the random number selected by the base station Nbs, selected by the base station and by The authorization key identifies the ciphertext Ekek (TEKM) of the session key material ΊΈΚΜ encrypted by the key encryption key derived from the authorization key corresponding to the AKID, and the validity period Lifeg message integrity check code MIC of the session key material TEKM, where: The value of the random number Nms selected by the mobile terminal should be negotiated with the key

200610104679.4 The corresponding fields in the request packet have the same value, and the value of the message integrity check code MIC is calculated using the integrity check key derived jointly by TEKM, Nms and Nbs; the content of the group should be confirmed by key agreement including: the identity of the base station The identity IDms of the mobile terminal, the security association identifier SAID, the authorization key identifier AKID, the session key identifier 1EKID, the random number selected by the base station, and the message integrity check code MIC. Among them, the value of the random number Mbs selected by the base station should be the same as The value of the corresponding field in the key agreement response packet is the same, and the value of the message volume check code MIC is calculated using the integrity check key derived from TERM, Nms, and Nb.

A multicast key peopleagement method, which is special in that: the implementation steps of the method include: (1) Multicast master key agreement protocol: (1.1) Constructing a key report group: The base station needs to update the session key, and When the mobile terminal has not submitted a request to update the session key, the base station will report the grouping of the key ΜΛ to the mobile terminal, and notify the mobile terminal of the return key and the knowledge key ΜΛ only to be resolved when the key is woven. The key is not negotiated.

(1.2) Constructing a key agreement request group: During the initial key agreement process, when the mobile terminal is comfortable with the key report, the mobile terminal sends a key agreement request group to the base station to activate the key agreement process; (1.3) Construct a key agreement response packet: (1.3.1) The base station is comfortable! | The key agreement request of the mobile terminal can construct a key agreement response (1. 3.2) If the base station sends a key update notification packet first, Then the base station checks whether the values of the corresponding fields in the key update notification packet and the key agreement request packet are the same. If they are the same, Bei0 constructs a key agreement response packet; if they are not the same, discard the key agreement request packet without any processing; (1.3. 3) The base station sends a key agreement response packet to the mobile terminal, and derives the multicast key encryption key GKEK and the multicast message integrity check key GMIK; (1.4) Construct a key agreement to confirm that the mobile terminal has received the base stations The key agreement response component is decrypted by the key encryption key derived from the authorization key corresponding to the authorization key ^iRAKID, and the session key material TEKM is obtained, and the key agreement confirmation group is constructed; the mobile terminal groups the key agreement confirmation Send to the base station. Export the multicast key encryption key GKEK and the multicast message integrity check key GMIK; (2) Multicast session key distribution protocol: (2.1) Multicast session key request: The mobile terminal needs to negotiate or update the multicast When the session key is used, the mobile terminal sends a multicast session key request packet to the base station;

200610104679.4 Section (2.2) Group Key Distribution: When the base station receives the multicast session key request packet sent by the mobile terminal, the base station sends the multicast session key distribution packet to the mobile terminal; or when the base station needs a multicast key update, the base station Broadcast the multicast session key distribution packet to all mobile terminals.

The content of the blood key update notification group includes: the identity IDbs of the base station, the security association identifier SAID, the authorization key identifier AKID, the session key identifier TEKID, and the message integrity check code MIC. Among them, the session key identifier IEKID is used to identify For the session key that needs to be updated, the value of the message integrity check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to AKID; the content of the above key agreement request packet includes: the identity of the mobile terminal %, The security association identifier SAID, the authorization key identifier AKID, the session key identifier TEKID, the random number Nms selected by the mobile terminal, and the message integrity check code MIC. Among them, the session key identifier IEKID is used to identify the session key that needs to be updated. The value of the message integrity check code MIC enables the integrity check key derived from the authorization key AK corresponding to ffiAKID to be calculated; the content of the key agreement response packet includes: the identity of the mobile terminal, the identity security association of the base station, and the authorization The key WUKID, the stolen key WTEKID, the TONms taken from the mobile terminal, the random number Nbs selected by the base station, the key encryption key selected by the base station and derived from the authorization key corresponding to the authorization key identification AKID Tongue key material TEKM's secret ^κεκ (ΤΕΚΜ), the effective speed of the tongue key, Message integrity check code MIC, where the value of the random number Nms selected by the mobile terminal should be the same as the value of the corresponding field in the key agreement request packet, and the value of the message integrity check code MIC is jointly derived using TEKM, Nms and Nbs The content of the above-mentioned key agreement confirmation group includes: the identity of the base station, the mobile terminals identity security association identification SAID, the authorization key identification AKID, the session key identification IEKID, the random number selected by the base station, Message integrity check code MIC, where the value of the random number Nbs selected by the base station should be the same as the value of the corresponding field in the key agreement response packet, and the value of the message integrity check code MIC is derived jointly by TERM, Nms and Nbs Integrity check key calculation.

The content of the multicast session key request packet includes: the security association identifier SAID, the session key identifier IEKID, the multicast session key identifier GTEKID, the random number Nms selected by the mobile terminal, and the message integrity check code MIC. Among them, the group The multicast session key identifier GTEKID identifies the negotiated or requested multicast session key, and the value of the message integrity check code MIC is calculated using the multicast message integrity check key GMIK derived from the TEKM corresponding to TEKID; The content of the key distribution group includes: security association identification SAID, session key identification TEKID, multicast session key identification GTEKID, random number Nms selected by the mobile terminal, and multicast key selected by the base station and derived from TEKM corresponding to TEKID The cipher text of the multicast session key material G1EKM (Eqke^GTEKM) encrypted by the encryption key GKEK, the validity period of the multicast session key LifeeiEK, the message integrity check code MIC, among which, mobile

200610104679.4 The random number Nms selected by the first terminal must be the same as the random number in the multicast session key request packet, but if it is a key update process initiated by the base station, the value of the random number can be determined by the base station itself, and the message integrity check The value of the verification code MIC is calculated by the multicast message integrity check key GMK derived from the TEKM corresponding to fflTEKID.

The present invention has the following advantages: (1) Different levels of session keys can be realized for different services. Different businesses have different encryption keys.

(2) Multicast session key negotiation makes reasonable use of broadcast channels and improves perforpeoplece. The base station does not need to negotiate with each mobile terminal key separately.

(3) The effective Mfh of the inter-cooperative real-time tongue key is distributed using the key agreement tongue key to make the update of the multicast session key more flexible.

(4) The key activation mechanism adopts the message confirmation method to avoid the shortcomings of time synchronization and multiple states, and simplifies state peopleagement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a unicast session key and a multicast master key agreement protocol of the present invention; FIG. 2 is a schematic diagram of a multicast session key distribution protocol of the present invention.

Refer to Figure 1 for specific implementation. The implementation steps of the network unicast key peopleagement method of the present invention are as follows: (1) Construct a key agreement request group: During the initial key agreement, or the mobile terminal requests a key update or receives a key update from the base station When the key update announcement packet, the mobile terminal sends a key agreement request packet to the base station to activate the key agreement process.

The content of the key report includes: the identity of the base station is associated with the authorization key ID AKID, the session key ID IEKID, and the message integrity check code MIC. Among them, the session key ID TEKID is used to identify the session key that needs to be updated. Key, the value of the message integrity check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to the AKID.

The content of the key agreement request packet of the above technique includes: the identity security association identifier SAID of the mobile terminal, the authorization key identifier AKΠΧ session key identifier TEKΠΧ mobile terminal selected with the money, the message integrity check code MIC, where the session The key identifier IEKID is used to identify the session key that needs to be updated, and the value of the message integrity check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to the AKID.

(2) Constructing the key agreement response group: (2.1) The key agreement request of the base station and the mobile terminal is divided to construct the key agreement response group.

The content of the other group of key agreement response includes: the identity of the mobile terminal, the identity security association identifier of the base station, the authorization key identifier AKID, the session key identifier TEKID, the random number selected by the mobile terminal%, the random number selected by the base station, Nbs, and the base station. Selected and derived from the authorization key corresponding to the authorization key ID AKJD

200610104679.4 The secret key material TEKM encrypted by the first key encryption key is the secret ΪΕκεκ(ΤΕΚΜ), the validity period LiZ of the key material TERM, and the message integrity check code MIC. Among them, the value of the random dish selected by the mobile terminal should be The value of the corresponding field in the key agreement request packet is the same, and the value of the message integrity check code MIC is calculated using the integrity check key jointly derived by TEKM, Nms, and Nbs.

(2. 2) If the base station sends the key update notification packet in advance, the base station checks whether the values of the corresponding fields in the key update notification packet and the key agreement request packet are the same. If they are the same, Beibu creates the key agreement response packet; if they are not the same, the key agreement request packet is discarded without any processing; (2. 3) The base station sends the key agreement response packet to the mobile terminal to derive the unicast session encryption key (3) Construct a key agreement confirmation group: The mobile terminal receives the key agreement response from the base station and uses the key encryption key derived from the authorization key O<AKID corresponding to the authorization key. The key is decrypted to obtain the session key material TEKM, and the key agreement confirmation packet is constructed.

The content of the key agreement confirmation packet includes: the identity of the base station, the identity of the mobile terminal, the security association identifier SAID, the authorization key identifier AKID, the session key identifier IEKID, the random number interval selected by the base station, and the message integrity check code MIC, Among them, the value of the random Nbs selected by the base station should be the same as the value of the corresponding field in the key agreement response packet, and the value of the message integrity check code MIC is calculated using the integrity check key jointly derived by ΊEKM, Nw, and Nbs.

Referring to Figure 2, the implementation steps of the multicast key peopleagement method of the present invention are as follows: (1) Multicast master key agreement protocol: (1.1) Construct key M »report group: The base station needs to update the session key, but the mobile terminal has not yet When requesting to update the session key, the base station notifies the mobile terminal and the key notification to the mobile terminal. The key notification is generally only triggered during the session key and not during the initial key negotiation.

The content of the session key update notification packet includes: the identity security association identifier SAID of the base station, the authorization key identifier AKID, the session key identifier TEKID, and the message integrity check code MIC. Among them, the session key identifier TEKID is used to identify the need to update The value of the message integrity check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to AKID.

(1.2) Construct a key agreement request packet: During the initial key agreement process, or when the mobile terminal receives a key update notification packet sent by the base station, the mobile terminal sends a key agreement request packet to the base station to activate the key agreement process ; The content of the key agreement request packet includes: the identity of the mobile terminal %, the security association identifier SAID, the authorization key identifier AKID, the session key identifier ΊEKΠ), the random number selected by the mobile terminal Nms, and the message integrity check code

200610104679.4 p.

MIC, where the session key identifier TEK1D is used to identify the session key that needs to be updated, and the value of the message hyper-check code MIC is calculated using the integrity check key derived from the authorization key AK corresponding to the ARID.

(1.3) Construct a key agreement response group: (1.3.1) Base station-U mobile terminal suspected key agreement request construction key agreement response The content of the total key agreement response group includes: the identity of the mobile terminal% and the identity of the base station %, security association identification SAID, authorization key identification ARID, session key identification TEKID, random number selected by mobile terminal, random Nbs selected by base station, authorization key selected by base station and identified by authorization key corresponding to AKID The derived key encryption key encryption key material TEKM secret jtEKEK (TEKM), the effective key plus the message integrity check code MIC, where the value of the random number Nms selected by the mobile terminal should be the same The values of the corresponding fields in the key agreement request packet are the same, and the value of the message integrity check code MIC is calculated using the integrity check key jointly derived by TERM, Nms, and Nbs.

(1.3.2) If the base station has sent a key update notification packet in advance, the base station checks whether the values of the corresponding fields in the key update notification packet and the key agreement request packet are the same. If the same, bei! J constructs the key agreement response packet; not the same, loses the key agreement request packet and does not deal with it; (1.3. 3) The base station sends the key agreement response packet to the mobile terminal, and derives the multicast key encryption key GKEK and group Broadcast message integrity check key GMK; (1.4) Construct a key agreement confirmation group: The mobile terminal receives the key agreement response from the base station, and then uses the key derived from the authorization key WiAKID to encrypt it. The key is decrypted to obtain the plaintext TEKM of the session key material, and the key agreement confirmation packet is constructed; the mobile terminal sends the key agreement confirmation packet to the base station. Export the multicast key encryption key GKEK and the multicast message integrity check key GMIK; the content of the key agreement confirmation packet includes: the identity of the base station, the mobile terminals identity security association identifier SAID, the authorization key identifier AKID, and the session secret The key identifier TEKID, the random number selected by the base station, and the message integrity check code MIC. Among them, the value of the random number Nbs selected by the base station should be the same as the value of the corresponding field in the key agreement response packet, and the message integrity check code MIC The value of is calculated using the integrity check key derived jointly by TEKM, Nms and Nbs.

(2) Multicast session key distribution protocol: (2.1) Group key request: When the mobile terminal needs to negotiate or update the multicast session key, the mobile terminal sends a multicast session key request packet to the base station; multicast session The content of the key request packet includes: the security association identifier SAID, the session key identifier 1EKID, the multicast session key identifier GTEKID, the random number Nms selected by the mobile terminal, and the message check code MIC, among which,

200610104679.4 The first multicast session key identifier GTEKID identifies the negotiated or requested multicast session key, and the value of the message integrity check code MIC is calculated using the multicast message integrity check key GMIK derived from the TEKM corresponding to the TEKID; (2.2 ) Multicast session key distribution: When the base station receives the multicast session key request packet sent by the mobile terminal, the base station sends the multicast session key distribution packet to the mobile terminal; or when the base station needs a multicast key update, the base station sends all The mobile terminal broadcasts the multicast session key distribution packet.

The contents of the multicast session key distribution packet include: security association identification SAID, session key identification TEKID, multicast session key identification GTEKID, random dishes selected by the mobile terminal, selected by the base station and derived from the TEKM corresponding to the TEKID Multicast key encryption key GKEK encrypted multicast session key material GTEKM cipher text EgkekQTEKM), the validity period of the multicast session key Π, the message integrity check code MIC, where the random number selected by the mobile terminal Nms It must be the same as the random number in the multicast session key request, but if it is a key update process initiated by the base station, the value of the random number can be determined by the base station itself, and the message integrity check code MIC value corresponds to TEKID The multicast message integrity check key GMIK derived from the TEKM is calculated.

Technical code notes of the present invention:

AKID: delete authorization key;

AKM: thin tongue key material;

TEKM: steal key material;

BS: base station;

E_K(M): The decryption key is as encrypted;

GKEK: group ^ key encryption key;

GMK: Multicast message integrity verification key;

LifeAK: the life or validity period of the authorization key AK;

LifeiEK: the validity period Li of the stolen key material TEKM;

N_bs: Random number selected by the base station BS;

N_ms: Random number selected by the mobile terminal MS;

IDbs: the identity of the base station BS;

IDms: the identity of the mobile terminal MS;

MIC: message integrity check code;

MS: mobile terminal client;

SAID: Security association identification, corresponding to a specific service, unicast SA^multicast SA can be distinguished by its ED;

TEKID: Delete the key.

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