KR101269761B1 - Key control devices, secure terminals and communication apparatus suitable for session key generation and security control in secure and mobile IP networks - Google Patents

Abstract

The present invention provides a key generation technology for safely and onlinely generating a session key and a session group key value used for each specific session in one-to-one communication or group communication and a key generated and used by a user in one-to-one communication or group communication for security control. The present invention relates to a key controller, a security terminal, and a secure communication device suitable for session key generation and security control in a secure mobile IP communication network configured to obtain a value safely, online, and in real time as a security control department.

Description

Key control devices, secure terminals and communication apparatus suitable for session key generation and security control in secure and mobile IP networks}

The present invention provides a key generation technology for securely generating the session key and the session group key value used for each specific session in one-to-one communication or group communication in real time online and for security control. The present invention relates to a key controller, a terminal, and a secure communication device suitable for session key generation and security control in a secure mobile IP communication network configured to securely obtain, on-line, and real-time key values to be used as a security control department.

The technology that solves the problem of using which key to encrypt a call by two people or a group who wants to call at that time is based on Diffie Hellman which is used in commercial IPSec. It is a key exchange technique.

Diffie Hellman based key exchange method is a global parameter of g and p that if they openly in a given state individuals have their own private key K, expression of a BK (K) his blind key (Blind Key) g ^K mod p After obtaining from the relationship, send the blind key to the other party.

In other words, it is a technique that can sufficiently create a session key while exposing blind key BK (K) without exposing K. A common session key can be generated by exchanging the blind key of the counterpart between both parties. If a user Ui having a private key Ki and a user Uj having a private key Kj try to communicate securely, they send their blind keys to each other, but mathematically

(g ^Kj mod p) ^Ki mod p = (g ^Ki mod p) ^Kj mod p = session key

As a result of this relationship, we can safely generate and use the session key value in real time while exposing only the blind key online. In addition, session group key is required for group communication, and additional key tree technology is required to apply Diffelmann-based key exchange scheme to a group.

The key tree is composed of key tree leaves and nodes. The leaf distinguishes a user's position in the tree, and a node represents an intermediate key value in an intermediate process for generating a group key.

If there are eight groups, the nodes consist of primary, secondary, tertiary and vertex nodes. To generate a group key, the key value on the direct path must be computed, starting from a key tree leaf and leading to the vertex node.

To do this, blind key values of primary, secondary, and tertiary counterpart nodes are required based on the Diffelmann-based key exchange technique. As a result, since the blind key values can be safely obtained online, the basic technique of safely obtaining the session group key is set as the background art.

The problem to be solved by the present invention is likely to operate a mobile IP network in the military, police, firefighting, emergency disaster rescue departments, etc. belonging to a special situation, security personnel can always legally intercept communication if necessary, The goal is to provide a mobile IP network with security that makes it impossible for others to eavesdrop.

Another problem to be solved by the present invention is that the private key value is given to the user in advance in order to provide a secure communication service to mobile IP network users. There should be no fear of exposure, and when one-to-one security communication or group security communication is made from the security control point of view, the session key and session group key used in real time can be found out to achieve thorough security control.

The problem solving means of the present invention is based on the Diffelmann based key exchange technique, the user requesting a call first sends the requester blind key concealing the requester's private key to the requester, the requestor in response Send the blind key hidden to the requestor so that both parties can generate the same session key, and only the call requester and the requestor's ID (identification number) are notified in real time. The present invention provides a key controller, a security terminal, and a secure communication device configured to find a private key of a requestor, calculate their blind key, and find out the same key value as a session key generated remotely (secure terminal) in real time.

Another problem solving means of the present invention is to generate a session group key based on a blind key exchange technique in real time, online, and securely every time a call is initiated so that the contents can be encrypted by group communication with several people. Built-in configuration in the security terminal, and receive only the ID (identification number) information of active user group members participating in group communication online in real time, without receiving session group key generated for group communication directly The present invention provides a key controller, a secure terminal, and a secure communication device suitable for session key generation and security control in a secure mobile IP communication network configured to calculate a session group key and securely control group communication.

Another problem solving means of the present invention is based on the Diffelmann-based key exchange scheme, the requester blind key concealed the private key of the call requester that the user requesting the call to the requester, and the requestor in response The requester blind key, which hides the requester's private key, which is sent to the call requester, and the callee and the requestor are notified in real time only of the session key and ID of the call requester and the requestor. Session key generation in mobile IP network that finds private key of call requester and requestee and calculates blind key of them and finds the same key value in real time with session key generated remotely (secure terminal) And key controller suitable for security control.

Another object of the present invention is to provide a security terminal having a user private key for interworking with a key controller, and a means for generating a session key based on a blind key exchange technique for encrypting one-to-one or group communication contents. To implement.

Another problem solving means of the present invention is based on the Diffelmann-based key exchange technique, the requester blind key concealed the requester's private key that the user requesting the call to the requester, and the requestor in response to the requester The requester blind key, which hides the requester's private key, which is sent to the callee, and the callee and the requester are notified in real time by receiving only the session key generated by receiving the other party's blind key, and the call requester and the requestor's ID. It finds the private key of the call requester and the called party and calculates the blind key of the call requester and the requester, and has a means to find out the same key value as the remotely generated session key in real time and the user private key. In order to achieve this, we construct a secure terminal that generates a session key based on the blind key exchange technique. It is to implement a secure communication device.

Another problem solving means of the present invention is that the TM sends the group ID (identification number) and the active user group member information to the key controller immediately after generating the session group key of the tree vertex by the control of the TM. Since the controller keeps the private key of each group participant in the database, it finds the relevant private key and calculates the blind key of the primary correspondent node on the TM direct path from the lowest level TM node to the vertex node in the key tree. Secure mobile IP network with key controller and key controller suitable for session key generation and security control in mobile IP network composed of means for calculating key value for secondary node on TM direct path according to Hellman-based key exchange technique To implement a key controller, a secure terminal, and a secure communication device suitable for session key generation and security control.

The present invention has a wide range of use, such as military network, national disaster prevention network, police police network, construction site network in a special situation, and can provide secure communication by paying security terminals to users of a geographically distributed mobile type. For example, a call of a security terminal mainly used by an institution may be intercepted by a security department to intercept a legally encrypted secure call, and may have an advantageous effect that a security control tracks and manages a secure call record.

Another effect of the present invention can be secure communication without the exposure of the private keys once paid to each user in order to form a secure communication online, and the security department can even security control In addition, the members who want to make a group call can securely obtain the session group key in real time, and the key controller can securely generate the session group key, which is an encryption key used by any group, in real time. It is to enable communication service and security control and control to security department.

1 illustrates a secure communication operation form between a key controller (KCD) and a security terminal.
2 illustrates a secure one-to-one communication session key generation procedure and a key controller session key security control procedure.
3 illustrates a key tree structure required for generating a session group key for multicast communication between groups.
4 illustrates a session group key generation procedure and a key controller session key acquisition procedure required for multicast communication between groups.
5 illustrates a method for generating a session group key for multicast communication between groups and a method for securing a session group key of a key controller.
<Brief Description of Drawings>
110; Black network 111; Red network
112; Wireless ad hoc network 113; Key controller
114; Wireless ad hoc node
120; p1JoinRequest message 121; p1JoinReply message
122; Session key (Ui side) 123; Session key (Uj side)
124; p1 JoinConfirm message 125; p4JoinReport message
126; Session key
140; TM 141; p1JoinRequest message
142; p1JoinReply message 143; p1BlindRequest message
144; p31BlindDist message 145; p32BlindDist message
146; p33BlindDist message 147; p4Report message
150; p1JoinRequest message 151; p2JoinReply message
152; p1BlindRequest message 153; p31BlindDist message
154; p32BlindDist message 155; p33BlindDist message
156; p4Report message

Hereinafter, the present invention will be described in detail. Looking at the application fields and technical fields of the present invention, military networks, national disaster prevention network, police police network, construction site network, etc., all moving according to the situation are all dedicated to institutions using IP (Internet Protocol) technology in the future. It will evolve into a mobile IP network.

The characteristic of communication service through mobile IP network is to provide secure communication by paying security terminals to mobile users of geographically distributed type. In addition, the call of this secure terminal used exclusively by the agency should be able to legally eavesdrop on the encrypted secure call by the security department, and security control should be made to track and manage the secure call record. Nevertheless, private keys, once issued to each user for secure communication, should never be exposed online. In this condition, it should be able to communicate securely, and the security department should also have a list of private keys paid to individual users, but they should be able to control security without the keys being exposed online.

The secure communication service type should be able to provide both one-to-one communication service, which is a bilateral call, and multicast group communication, in which several members communicate together.

The technical field of the present invention is one-to-one communication as well as one-to-one communication for security control (Key Control technology) and key generation technology for generating secure, online, and real-time session keys and session group key values used for specific sessions in group communication. Key controller, security terminal, and security suitable for session key generation and security control in a secure mobile IP network configured to securely, online and in real time, identify key values generated and used by users in group communication as a security control department. It relates to a communication device. A specific embodiment according to the present invention will be described.

<Examples>

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will now be described with reference to the drawings. The following is a detailed description of FIG. 1. 1 illustrates an operation mode of a key controller (KCD), a security terminal, and a secure communication device using the same. In order to explain the present invention, it is first necessary to clarify the scope of application of a mobile IP network. A network with a movement of the network itself, rather than a commercial Internet network, is called a 'mobile IP network'.

In particular, for the sake of easy understanding of the present invention, a network dedicated to a special situation which is intended to be used in a future state special situation (military network, national disaster prevention network, police security network, construction site network, etc.) Since the characteristics are well represented, the present invention will be described through an example of the special situation dedicated network.

The mobile IP network can be divided into three parts: first, a black network in the form of a VPN (Virtual Private Network) using a commercial Internet as a tunnel, and second, a tactical network dedicated to an arbitrary group that can move as the random group moves in a special situation. Red network of the form, the third communication node is composed of a wireless Ad hoc network that also serves as a terminal.

In order to provide a secure communication service to a user using a mobile IP network, the communication content must be encrypted and transmitted. To do this, each user must be assigned a private key for encryption.

That is, a private key is assigned to the user terminal. The key controller 113, that is, the KCD (Key Control Device), holds the entire information of the private keys assigned to the user terminals.

There are two types of services provided by the secure communication device according to the present invention. One is quantum communication (Unicast, referred to as 'one-to-one communication' in the present invention), and the other is multicast. ) Group communication (hereinafter referred to as 'multicast communication' or 'group communication').

For example, one-to-one communication is performed between user Ui and Uj, and group communication is performed between user groups U1, U2, U3, ..., U7, and U8. Thus, as a result, the key controller has a list of private key information assigned to each user, and also has a group member configuration list, that is, a list indicating which group is composed of which members.

On the other hand, the security terminal has a group ID (identification number) indicating which private key information is given to it and which multicast group it belongs to.

Security is most necessary in the operation of mobile IP networks, but security control must be satisfied at the same time. This is because mobile IP networks are most likely to be operated by the military, police, firefighting and emergency disaster relief departments, and security control personnel should be able to legitimately intercept communications when necessary. In some ways, security and security seem to contradict each other.

Therefore, these two characteristics, that is, to provide a secure communication from the user's point of view, and to the security authority to be able to intercept the user's communication at any time is a key technical configuration to be solved by the present invention.

The following is a description of FIG. 2. 2 is a session key generation procedure for secure one-to-one communication and session key security control procedure of the key controller. It describes a method of obtaining a key value (hereinafter referred to as a 'session key') for encrypting a call at the beginning of one-to-one call and a technical configuration for reporting the generated session key value to a key controller.

The key point of the technical configuration of the present invention is that no one except the key controller controlling the two user terminals Ui and Uj to call can find out the session key.

This technology is basically based on Diffie-Hellman-based key exchange. First, a Uj requesting a call sends a p1JoinRequest message 120 to Ui, the requester. This message contains BK (Kj), which is a blind key to Uj's private key Kj.

The relationship BK (Kj) = g ^Kj mod p holds, meaning 'key that hides Kj information'. The g and p values are global parameters defined by the Diffelmann-based key exchange scheme, both of which know in advance.

G ^Kj mod p is g ^Kj The remainder of the value divided by the p value.

Ui who has received BK (Kj) creates a blind key BK (Ki) using his private key Ki and sends it to Uj by putting it in p1JoinReply message 121.

Then you are notified of each other's blind key.

Ui then calculates Ki ○ BK (Kj) = (BK (Kj)) ^Ki mod p = (g ^Kj mod p) ^Ki mod p (122) to find the session key Kij,

Uj calculates Kj B BK (Ki) = (BK (Ki)) ^Kj mod p = (g ^Ki mod p) ^Kj mod p (123) to obtain the session key Kji.

After all, the equation (g ^Kj mod p) ^Ki mod p and the expression (g ^Ki mod p) ^Kj mod p have the same value and Kij = Kji, so Ui and Uj specify the session key value to use to encrypt the currency. Share online securely in real time.

Of course, it is preferable to add an authentication procedure for confirming the other party in this process, but since the authentication procedure is generally widely used, detailed descriptions are omitted in the present invention.

The next step is to configure the key controller for security control. Ui sends a p4JoinReport message 125 to the key controller. This message only contains ID information of Ui and Uj.

After receiving the p4JoinReport message, the key controller finds Ki and Kj, which are private keys of Ui and Uj, from the list of private keys owned by him and then uses Ki and Kj.

Kij = (g ^Kj mod p) Evaluate using the ^Ki mod p equation

You can get the session key Kij. At this time, the key controller records the time and Kij information that U _i and U _j make K _ij .

This record information can be used for real-time monitoring, that is, security control, and it is important information for the security department because it can manage the record using the private key.

The following is a description of FIG. 3. 3 is a diagram illustrating a key tree structure required for generating a session group key for multicast communication between groups. The key controller maintains a list of which groups are made up of which members. On the other hand, the security terminal has a group ID (identification number) indicating which multicast group it belongs to. 3 is a group member list managed by a key controller when eight specific groups participate in group communication.

The group member list is managed in a key tree along with the private key given to the individual member. As shown in FIG. 3, eight persons U ₁ , U ₂ , U ₃ ,..., U ₈ correspond to a key tree leaf, and each node of the tree has a unique number and location information. Nodes are classified into primary, secondary, tertiary, and vertex nodes, and nodes are divided into primary, secondary, and tertiary corresponding nodes, and the path from the key tree leaf to the vertex node is called a 'direct path'. ' The characteristic of the key tree is that all nodes have the same number of children. This is expressed as a tree degree, and FIG. 3 shows a case where the tree degree is two.

In the case of using the key tree from the user's point of view, only the key values of nodes in the direct path from themselves to the vertex node are calculated. And the key K _{1 -8} group key K _G corresponding to the apex node of the key tree, which will be meeting in the apex node because all the group members, each from his own share of K _{1 -8.}

For example, user U ₄ holds K ₄ in advance, and receives K ₃₄ , K _{1 -4} , K ₁ after receiving the blind key of the node's primary, secondary, and tertiary counterparts. You can calculate _-8 . Eventually K _{1 -8} becomes K _G.

On the other hand, the key controller holds the entire key tree, which eventually gives K _{1 -8} (K _G ) that this particular group will use as a common session key.

The following is a description of FIG. 4. 4 is a method for obtaining a session group key for use in call encryption by a multicast group and a procedure for reporting the session group key to a key controller.

For reference, the description of the procedure for user authentication will be omitted here as well. The group key is also the session key that is generated at the beginning of the call and used until the end of the call. Thus, the user requesting a call is granted TM (Transaction Manager, 140) qualification in creating this session group key.

First, suppose that U8 requested a group call. U8 then multicasts the p1JoinRequest message 141 to its group members with TM status. Each group member who receives the p1JoinRequest message sends a p2JoinReply message to the TM indicating whether he or she can join the group call.

Upon receiving the p2JoinReply message, the TM distinguishes who can participate in group communication and who cannot participate, and creates an active user tree and puts it in a p1BlindRequest message to multicast to the group members.

The active members in the group receiving the p1BlindRequest message make a blind key of the primary node and put them in the p31BlindDist message to multicast. Active members in the group receiving the p31BlindDist message generate a blind key corresponding to the secondary node on the direct path of the tree, and load the multicast key in the p32BlindDist message. The active members receiving the p32BlindDist message also multiply by creating a blind key corresponding to the tertiary node in the hierarchy and putting it in the p33BlindDist message.

Through this process, the active group members can calculate the key values for the secondary node, the tertiary node, and the vertex node on the direct path, respectively, and the last calculated key value of the vertex node becomes the session group key.

The status report that generated the session group key is configured so that the TM is the only key controller. To do this, the TM sends a p4Report message to the key controller. The p4Report message includes only active user tree leaf information. Because the key controller already has the private keys of these group members, knowing who actually participates in the group communication can create the same session group key as the session controller initiated by the key controller itself. Therefore, security control and security call management, which are important roles of the key controller, can be effectively performed.

The following is a description of FIG. 5. 5 specifically illustrates how a group key is generated when U4 and U5 are absent from a group call when U8 attempts a group call in a specific group. U8 becomes TM qualified to multicast p1JoinRequest message 150 to its group members. The group members who have received the p1JoinRequest message send a p2JoinReply message 151 to the TM.

The TM receiving the p2JoinReply message creates a group communication participant list [U1, U2, U3, x, x, U6, U7, U8] by dividing the availability and inability to participate among the group members and implements it in the p1BlindRequest message 152. Go ahead and multicast to the group members. Active members in the group that received the p1BlindRequest message were U1 for BK (K1), U2 for BK (K2), U3 for BK (K3), U6 for BK (K6), U7 for BK (K7), U8 for BK (K8 ) Are loaded into p31BlindDist message 153 and multicasted.

The active member U1 or U2 in the group receiving the p31BlindDist message creates BK (K12) and U7 or U8 creates BK (K78), respectively, and puts it in the p32BlindDist message 153 and multicasts it.

Active members that receive the p32BlindDist message create BK (K1-3), one of U1, U2, and U3, and one of U6, U7, and U8, BK (K6-8), respectively, and multicast to the p33BlindDist message. do.

In the example in which U3 generates a session group key, first, K3 B BK (K12) is calculated using BK (K12) obtained after receiving a p32BlindDist message to calculate K1-3. Next, K1-3 ○ BK (K6-8) is calculated using BK (K6-8) obtained after receiving the p33BlindDist message to generate K1-8. The generated K1-8 becomes the session group key K _G for U3. In this way, the remaining group members also generate a session group key K _G.

Immediately after generating the session group key of the tree vertex node under the control of the TM, the TM sends the group ID and active user group member information [U1, U2, U3, x, x, U6, U7, U8] to the p4Report message (156). Load it and send it to the key controller.

The key controller receiving this information keeps the private key of each group participant, so finds the relevant private key and calculates the blind key of the primary correspondent node on the TM direct path from the lowest level TM node to the vertex node in the key tree. Compute the key value for the secondary node on the TM direct path according to the Diffiemann-based key exchange scheme, calculate the blind key value for the secondary counterpart node, and then use it to calculate the value of the 3 Compute the key value for the secondary node.

Finally, after calculating the blind key value for this tertiary counter node, the key value for the vertex node is calculated using the Diffelmann-based key exchange method, which is created by active user group members based on TM. The key controller is configured to calculate the same session group key.

In this way, the key controller generates the session group key K _G in the same way as the group members did, stores it, and uses it for real-time security control or security management.

As described above, private keys of all user terminals are not exposed online. Therefore, the members who want to call the group can get the session group key in real time safely, and the key controller can securely obtain the session group key, which is the encryption key used when any group calls, in real time. do. Security control in the present invention means having a function and means for intercepting a legally encrypted security call and tracking and managing the security call record.

From the above-described configuration, a key controller, a secure terminal, and a secure communication device using the key controller and the secure terminal are summarized.

First, the technical configuration of the key controller will be described.

The key controller is based on the Diffelmann based key exchange technique, receives only the caller's and the requester's IDs in real time, and calculates the requester's blind key by finding the private key of the caller and the requester in advance. And means for retrieving in real time the same key value as the session key generated by the call requester and the requestee security terminal with the call requester's private key and requestee blind key.

The key controller receives only the call requester and the requester ID information online in real time without receiving the session key generated for the one-to-one communication directly from the call requester and the requestee terminal, calculates the session key to be used, and secures one-to-one communication. It is provided with a means capable of.

The member list for each group of the key controller includes a private key of the entire key tree leaf (all group members), and has means for holding a user private key list and performing security control.

In addition, the key controller does not directly receive the session group key generated by the call requester and the requestee terminal for the group communication, and receives only the ID (identification number) information of the active user group members participating in the group communication online in real time. It is provided with a means to securely control group communication by calculating and generating a session group key to be used.

The key controller receives only the call requester and the requestee's ID (identification number) in real time, finds the call requester and the requester's private keys in advance, calculates their blind keys, and generates them. Means for finding out in real time the same key as the session key generated by the terminal).

Each node of the tree has a unique number and location information, and is configured such that all nodes have children of the same number.

The key controller receives the p4JoinReport message from Ui, finds Ki and Kj, the private keys of Ui and Uj, in the list of private keys it owns, and then expresses the private keys Ki and Kj (g ^Kj mod p) ^Ki mod A means for calculating the substitution key in p to obtain the session key Kij is provided.

When the key controller obtains the session key Kij, the key controller is configured to record and store, in memory, the time and Kij information that U _i and U _j make K _ij .

Next, the security terminal will be described.

The security terminal includes a user private key for interworking with a key controller, and means for generating a session key based on a blind key exchange technique for encrypting one-to-one or group communication contents.

The security terminal has a group ID (identification number) indicating which multicast group it belongs to, and the session key is based on the Diffiehlmann-based key exchange technique. Sending the requester blind key concealing the private key, the requester has a means for sending the requester blind key concealing the requester's private key to the requester to generate the same session key.

The secure terminal is configured to reuse a session group key generated once after generating a session group key based on a blind key exchange technique that is performed securely online in real time whenever a call is started in the next group call. Has a means for calculating and generating only the keys corresponding to the tree nodes on the direct path from each member's own key tree leaf to the vertex node.

The security terminal grants a call requester requesting a call to a TM, which is valid only for the current call period, and the TM multicasts a group communication request message to its group members. Each of them sends a response message indicating whether group communication is possible.

Upon receiving this message, the TM creates an active user group with only those who can participate in group communication, and multicasts the group members by putting key tree leaf information, which is the active user group information, in the blind key request message.

Active user group members who receive this blind key request message start the blind key values corresponding to the node in the direct path from their lowest node in the key tree to the vertex node, starting with the primary node, the lowest layer in the tree. It is configured to sequentially multicast by hierarchical steps.

Since the security terminal can know the blind key of the primary correspondent node, which is the lowest layer in the key tree of each active user group member, the blind key for the second layer on the direct path, that is, the secondary node, according to the Diffeemann-based key exchange scheme. Calculates and generates a blind key value for the secondary correspondent node, and uses it to calculate and generate a blind key for the third node, which is one higher layer on the direct path, according to the key exchange technique. Since the blind key value for the third correspondence node is received, the blind key value for the vertex node is calculated and generated according to the key exchange method, and used as the session group key.

The security terminal may be configured wirelessly or wired.

A secure communication device using a key controller and a security terminal is summarized.

The secure communication device is based on the Diffeemann-based key exchange technique, the requester blind key concealing the private key of the call requester sent to the requester by the user requesting the call, and the requester is transmitted to the call requester in response thereto. The caller blind key, which hides the requestor's private key, and the call requester and the requestor are notified in real time only of the session key generated by receiving the blind key of the other party, and the call requester and the requestor's ID in real time. In order to find the requester and the requester's private key, calculate their blind key and find out the same key value as the remotely generated session key in real time, and user private key, and to encrypt one-to-one or group communication contents. Means for generating session keys based on blind key exchange .

The secure communication apparatus includes means for receiving only the call requester and the requestee ID information online in real time without receiving the session key generated for the one-to-one communication directly from the call requester and the requestee terminal, and generating a session key for use thereof.

The secure communication device receives the p4JoinReport message from Ui, finds the private keys Ki and Kj of Ui and Uj in the list of private keys it owns, and then expresses the private keys Ki and Kj Ki (g ^Kj mod p) ^Ki. It has a means to calculate by substituting mod p.

In addition, the secure communication device does not directly receive the session group key generated by the call requester and the requestee terminal for group communication, and receives only ID (identification number) information of active user group members participating in the group communication in real time online. And means for calculating and generating session group keys for use by them to securely control group communication.

The secure communication device receives only the ID (identification number) of the call requester and the requestor in real time, finds the call requester and the requester's private keys in advance, calculates blind keys thereof, and generates and generates them. Means for finding out in real time the same key as the session key generated by the requester terminal).

Since the secure communication device can know the blind key of the primary correspondent node, which is the lowest layer in the key tree of each active user group member, the key for the second layer on the direct path, that is, the secondary node, is based on the Diffiehlmann-based key exchange scheme. Calculates and generates a value, and since it receives the blind key value for this secondary corresponding node, it is used to calculate and generate the key for the third node, which is one higher layer on the direct path, according to the key exchange technique. Since the blind key value for the third correspondent node is received, the key value for the vertex node is calculated and used according to the key exchange method, and the means is used as the session group key.

The secure communication device has means for calculating and generating only the keys corresponding to the tree nodes on the direct path from each member's own key tree leaf to the vertex node.

The secure communication device is configured to generate and use a session group key based on a blind key exchange technique in real time, online, and securely every time a call is started, and then reuse the generated session group key in the next group call. It is.

The present invention provides a key generation technology for securely generating the session key and the session group key value used for each specific session in one-to-one communication or group communication in real time online and for security control. Can provide key controller, secure terminal and secure communication device suitable for session key generation and security control in secure mobile IP communication network configured to securely find the key value to be used as security control department safely, online and in real time. Therefore, the industrial availability is very high.

Claims (21)

In the key controller,
A call requester blind key concealing a call requester's private key, which is information transmitted by a call requester requesting a call to the requestee based on a Diffelman based key exchange technique;
Requested blind key that hides the requester's private key, which is information transmitted by the requestor to the call requester in response to the call requester;
The call requester and the requestor each have a session key generated by receiving a blind key of the other party; And
Only the caller and the requester's ID are notified in real time, finds the caller and the requester's private keys in advance and calculates the blind keys of the caller and the requester. With means to find out,
The key controller holds a list of group members, has Kitley with a private key assigned to the individual member, Kitley has nodes, each node has a unique number and location information, and all nodes have the same number of children. It generates the session group key to be used by receiving only the ID information of active user group members participating in group communication online in real time without receiving the session group key generated from call requester and requestee terminal directly for group communication. And a key controller used for session key generation and security control in a mobile IP communication network having means for securely controlling group communication. delete delete delete delete delete The method according to claim 1,
The key controller receives the p4JoinReport message from Ui, finds Ki and Kj, the private keys of Ui and Uj, in the list of private keys it owns, and then expresses the private keys Ki and Kj (g ^Kj mod p) ^Ki mod A key controller characterized by obtaining the session key Kij by assigning to p. The method of claim 7,
When the key controller obtains the session key Kij, the key controller records and stores the time and Kij information in which the U _i and U _j make K _ij in a memory. In the terminal,
It has a user private key linked with the key controller,
Based on the Diffelmann-based key exchange technique to encrypt one-to-one or group communication content, the user requesting the call sends the requestor blind key, which hides the requester's private key, in response. Send the blind key, which hides the requester's private key, to the call requester to generate the same session key.
In the case of group communication, it has a group ID indicating which multicast group it belongs to.
In the case of group communication, the terminal is configured to calculate and generate only the keys corresponding to the tree nodes on the direct path of each group member starting from their own key tree leaf to the vertex node. delete delete The method according to claim 9,
The terminal is configured to generate and use a session group key based on a blind key exchange technique in real time and online whenever a call is started, and reuse the generated session group key in the next group call. . delete 13. The method of claim 12,
The terminal is given a TM qualification valid only during the current call period to the call requester, TM multicasts the group communication request message to its group members, and each group member who receives the message is able to participate in the group communication to the TM. The TM sends an informing response message, and the TM receives an active user group using only those who can participate in group communication, and adds key tree leaf information, which is the active user group information, to a group of group members by using a blind key request message. The active user group members that receive the blind key request message each receive blind key values corresponding to nodes on the direct path from their lowest node in the key tree to the vertex node. Starting with the nodes and sequentially Tea terminal configured to cast. 13. The method of claim 12,
Since the terminal can know the blind key of the primary correspondent node, which is the lowest layer in the key tree of each active user group member, the terminal determines the blind key value for the secondary node, which is the upper layer on the direct path, according to the Diffelmann-based key exchange scheme. Since we have received the blind key value for this secondary corresponding node, we use it to calculate and generate the blind key for the tertiary node, which is one higher layer on the direct path, according to the key exchange technique. Since the blind key value is received for the corresponding corresponding node, the terminal calculates and generates a blind key value for the vertex node according to the key exchange method using the same as the session group key. delete In a secure communication device having a key controller and a terminal,
A requester blind key based on the Diffelman based key exchange technique and concealing the private key of the call requester which the user requesting the call transmits to the requester;
The respondent may include a requester blind key that hides the requestor's private key, which is sent to the caller in response;
The call requester and the requestor each have a session key generated by receiving a blind key of the other party;
Only the caller and the requester's ID are notified in real time, finds the caller and the requester's private keys in advance and calculates their blind keys so that they have the same key value as the session key generated by the caller and the requester's terminal. Means for finding out in real time;
Means for generating a session key based on a blind key exchange scheme for encrypting one-to-one or group communication content with a user private key;
Instead of receiving the session group key generated by the call requester and the requestee terminal directly for group communication, it receives the ID information of the active user group members who participate in the group communication online in real time and calculates and generates the session group key for use. Means for security control; And
For security control, only the call requester and the requestee's ID are notified in real time, finds the call requester and the requester's private keys in advance, calculates their blind keys, and generates the session keys. And a means for finding out the same key in real time. delete 18. The method of claim 17,
The session key receives the p4JoinReport message from Ui, finds the private keys Ki and Kj of Ui and Uj in the list of private keys it owns, and then expresses the private keys Ki and Kj (g ^Kj mod p) ^Ki mod Secure communication device characterized in that obtained by substituting for p. delete delete

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