JPH05503816A - Method for authenticating and protecting subscribers in telephone communication systems - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] of subscribers in a telephone communication system Methods for authenticity and protection Technical field TECHNICAL FIELD This invention relates generally to communication systems and more particularly to radio frequency (RF) Relating to cellular communication systems.

Background of the invention Cellular radiotelephone systems typically connect fixed network communication units by means of RF transmissions. includes a subscriber unit (such as a mobile or portable unit) that communicates with the unit . A typical fixed communications network consists of at least a base station and a switching center. Including data. One responsibility of the fixed network communication unit is the requesting subscriber unit. communication system to the subscriber unit after the subscriber unit satisfies the system's authentication requirements. It is to approve the use of. In a typical cellular telephone communication system, each The subscriber unit has a telephone number (mobile identification number) (MIN) and one of the fixed An identification number (or Serial number) (SN) is assigned. Each subscriber unit shares it with other subscribers. It has a unique identification number that distinguishes it from the unit. fixed network communication unit accesses these identification numbers through a database. These numbers are Frequently fixed network communication units are used to track the amount of time a subscriber uses the system. used to bill subscribers. call a subscriber or other unit When he calls, he enters the phone number he wants to call. Dialed phone number is fixed This results in data to be sent to the network communication unit. Data is also a unit may contain other information about the third communication unit, such as the location of the third communication unit. Wear.

Detection of legitimate subscriber identification numbers may be accomplished by RF interception or by the wireless telephone installer. This can be caused by intentional or inadvertent omission of the MIN/SN combination by Ru. Once a subscriber's phone number and identification number are known (stolen), the thief Reprogram a stolen identification number to another subscriber unit and add two or more subscriber units have the same MIN/SN combination. cellular Wireless telephone systems are designed to deny access to subscribers who do not have a valid identification number. has an authentication procedure for multiple users, but detect or effectively counteract the effect of the installer divulging the subscriber identification number. have no ability. The legitimate user is therefore responsible for both the thief's use and his own use. You will be charged a fee for this.

Several authentication techniques are known. EIA-553, Section 2.3 Specifies that each subscriber should have a MIN and a factory set SN. Canada The telephone number on which the subscriber is attempting to contact is provided by the subscriber as a fixed network communications unit. This is the data sent to the knit. MIN and corresponding SN are fixed network If it is detected in the database of the communication unit, this system will authenticate it. Approved. Unfortunately, EIA-553 is not suitable for fixed network communications units. does not require encryption of kiIN or SN before transmission of either -Allowing direct RF detection of IIN or SN. Furthermore, this technology Provides no protection against thieves who obtain M I N/S N from the installer.

Other authentication technology is Groupe 5special Mob i l e ( GSM) as described in the European Cellular Communication System Recommendations produced by ing. See Sections 02.09, 02.17, 03.20 and 12.03. Light. The method further includes fixing a temporary mobile subscriber identity (TMS I) to the subscriber. Requires the network communication unit to transmit openly and The network communication unit generates and sends a random number (RAND) to the subscriber. Ru. This encryption technique allows the subscriber unit to retrieve at least three cryptographic requirements from its memory. SN (individual Subscriber Authenticity Key) and MIN (International Mobile Subscriber Identity Number - IMS I). The subscriber then encrypts its SN and MIN using the cryptographic key. and construct RAND into the signed response (SRES). The subscriber unit The response to the input is sent back to the fixed network communication unit, and the response is sent back to the fixed network communication unit. The network communication unit sends the SN, MIN and encryption key to the subscriber's temporary ID ( Check against that database using TMS.

The fixed network communication unit uses the information obtained from the database to sends the response to the fixed network number and the response signed by said subscriber. and the response generated by the network communication unit. If the responses are substantially equivalent If so, the authenticity is verified. The dialed phone number will be sent after the authenticity certificate is approved. It is permissible to send only to This system requires MIN/SN from the installer. The SN is encrypted against thieves who obtain it, and is unique every time the subscriber enters a different cell area. Protection can be provided by reallocating the temporal TMSI.

Some technologies encrypt subscriber serial numbers before transmission, but neither system also does not detect multiple users. Detecting a thief once he gains access Important for maintaining a secure system. Additionally, (required for encryption) The sending of a random number (with requires additional communication with the fixed network communication unit, which reduces transmission errors. authentication protocol for fixed network communication units. Add a send step to the process.

Additionally, proof of authenticity must be verified before allowing the system to accept data. Must be. Therefore, the data should not be sent after the steps in the authentication procedure are completed. There must be. Detect fraudulent users and efficiently authorize identification numbers Substantially enhanced protection for cellular telephone communication systems from unauthorized detection There is a need for authentic authentication technology. The authentication method is used to prevent inadvertent access. should limit the ability of unauthorized users to exploit the system if authorized by . Furthermore, an adequate level of security resulting from cryptography should require additional transmission processing. or should inject a higher level of error during the authentication process. It hasn't come yet.

Summary of the invention These needs and others are addressed by the additions in telephone communication systems disclosed below. Substantively satisfied by the provision of a method for authentication and protection of entrants. this The method includes a first communication unit, such as a subscriber unit, and a fixed network communication unit. authentication technology for use with a second communication unit, such as a communication unit; , in which case the first communication unit (such as a serial number) The ID is encoded in one code, known to both the communication unit and the second communication unit. Data as keys and other cryptographic keys (such as unique identification numbers - PINs) ) Change using the second ID. of the number of telephone calls generated by a certain subscriber historical non-arbt of a given communication event, such as counting trary) values are maintained in the first and second communication units. Said value (count g) is historical, because it is a communication unit's past Because it represents a telephone call, and it is non-optional, the reason is that this process Because history (number of calls generated) helps identify out-of-sync communication units It is.

The first communication unit communicates the changed ID and count (via RF multiplication signal) to the first communication unit. 2 communication unit. The second communication unit is activated by the first communication unit. Comparing the maintained count with the count maintained by the second communication unit . A discrepancy in counts indicates calls with different numbers on one unit Indicates multiple users who are out of sequence. The second communication unit has the same encryption method using the received data and the known serial number using the known second ID. Performed for the number. The second communication unit receives the modified serial number and Compare the serial numbers generated by the fixed network communication unit and Determine whether the file number is valid. The present invention provides an overview of the first ID of a certain communication unit. It is contemplated to substantially reduce unsolized usage. Authenticity certification method does not require the second ID to be transmitted by RF.

This invention detects multiple subscribers using the same serial number and telephone number. provide a means to In addition, if multiple users copy and If the same information is used to access the system, the user can Calling the phone number in the authenticity message instead of the phone number selected limited only. This authentication invention also applies to transmitted data and a second ID. use them as part of an encoder by making more efficient use of This reduces errors in authentication, and the encryption means are based on a common The additional R transmitted by the fixed network communication unit to be used as AND stream and thereby eliminate this additional transmission and Reduce the probability of errors.

Brief description of the drawing Figure 1 shows a typical subscriber communication unit and fixed network communication unit. FIG.

FIG. 2 is a flowchart illustrating the identification encryption method used by the subscriber communication unit. It is a chart.

FIG. 3 shows an authentic It is a flowchart showing a proof method.

FIG. 1 generally shows a subscriber communication unit (10) such as a subscriber telephone and a cell fixed network communication units such as telephone base sites and switching centers ( 20) is shown. The subscriber communication unit (10) includes a microprocessing stage (12), It comprises a volatile memory unit (11) and a radio frequency (RF) stage (13). All of these are technically well understood. Additional elements (phone number - data a data entry stage (14), such as a keypad on top of a telephone; A subscriber call sequence counter (15) and a cryptographic code called an encrypted serial number. Contains the output (16) from stage No.

In the non-volatile memory unit (11) there is a serial number (for the subscriber unit). (18), PIN (19), and (for example, Mobile Identification Number (MI) There is a subscriber telephone number (17) which may have the characteristics of N). PIN is a second ID known only to subscriber units and fixed network units. . For example, it is not something that should be available to the subscriber unit installer; This is a legitimate use of databases in subscriber units and fixed network communication units. should be made available only to those who use it. The subscriber must use the PI to activate it. You only need to enter N once. The PIN can be changed by the subscriber; Fixed network units must also be informed. These identifiers any attribute that can be identified by a fixed network communication unit, not necessarily a It can be made to correspond to. For example, another implementation in a cellular system An example is a stored lookup that includes multiple sets of serial numbers, PINs, and phone numbers. map table, where each set of identifiers is associated with a particular cellular region or fixed network. corresponds to the network communication unit.

The fixed network communication unit (20) includes a microprocessing stage (22), a database (23), and a link (21) to the base site radio frequency stage. These are all technically well understood. Additional elements include fixing screws. network unit call sequence counter (24) and fixed network unit Contains an encrypted serial number (25) generated by the cut.

The database contains information about the subscriber unit, namely the serial number (28) , PIN (27), and subscriber telephone number (26), the information is Stored subscriber number (28), PIN (27), and subscriber phone number (26) Contains copies. Serial number (18) and PIN of subscriber communication unit (10) (19), and the telephone number (17) is the fixed network communication unit (20) The serial number (28), PIN (27), and phone number ( 26). Subscriber communication unit (10) and fixed network communication unit Communication between 1 and 2 (20) follows well-understood cellular system techniques. This is done by RF transmission between the two units.

If authentication of the subscriber communication unit (10) is required, the subscriber unit encrypts its serial number (18) and its call sequence counter (15) Increment.

Figure 2 shows the transmission to the fixed network communication unit during the authenticity request (29). used by a subscriber communications unit to encrypt its serial number before transmission Show how it is done. This method requires the use of two encryption keys.

The subscriber unit obtains the called telephone number (data) (30) and enters the PIN (3). 1) from memory and at least some of these two elements by their serial numbers. is used as an encryption key to encrypt the code (32). If the PIN and If the discovered phone number consists of multiple bits, these keys are The parts are the contents of the bits and the bit length of each key. For example, encrypted The serial number is an unencrypted serial number or the latest unaltered serial number. The initial ID has different bit lengths depending on the PIN or data content. Maybe. Variations in the bit length of the encrypted SN also affect subscriber and fixed network It can also be a function of other events, such as the date and time known to the network unit.

The algorithm for combining two encryption keys varies depending on the system requirements. can be modified to provide different levels of security. The subscriber identification encryption method is Authenticity must be verified by a fixed network communications unit before being transmitted. do not need. Combining data with PIN can be authorized by RF interception. virtually eliminates unauthenticated detection and unauthorized leakage by deployers. Adds the ability to encrypt the serial number into a code complex enough to remove it. Ru.

The changed serial number (encrypted SN) is sent to the fixed network via RF (36). Authenticity request message (ARM) (35) sent to network communication unit It becomes an element of Once the encryption is complete, the assigned phone number will be retrieved from memory. (33) This number is not encrypted as part of the authenticity procedure. This knowledge Is Besshi a subscriber unit whose authenticity request is valid for a fixed network unit? This is an element of the ARM (35) that notifies you of the arrival of the host.

A call sequence count is then obtained (34) and used in the ARM (35). used. Call sequence counts count when an authentication procedure is initiated or a call is completed. updated (incremented or is decremented). This count is calculated by subscribers and fixed network units. It can be maintained using a rollover counter such as a ring counter. this The count includes calls generated by each subscriber by a fixed network communications unit. used as a means to count the number of Number of calls generated by each subscriber records are maintained by both the subscriber unit and the fixed network communications unit. other subscribers who wish to use the same serial number will be able to verify that it is a legitimate addition. This is detected because you are not generating exactly the same number of calls as there are incoming calls. call sequence count The information is an element of the authenticity request message to the fixed network unit. and communicated. ARM in any acceptable format or number You can communicate at this stage. The components of a typical AR,M(35) are data, encrypted Contains assigned serial number, call sequence count, and assigned phone number . Another embodiment could use the same encryption method used to change the SN. including changing the test count. This further increases protection, but its The reason is that said counts can also be disguised using PINs and data. This is because each subscriber gives a different value for the same count (number of calls generated). can occur.

The fixed network communication unit receives the transmitted ARM and authenticates this information. Used to determine whether a certificate should be approved for a subscriber unit.

FIG. 3 shows an authentication method performed by a fixed network unit. A.R. M received by the base RF unit (21) by the fixed network unit (37) A fixed network unit has a valid Access the subscriber unit's assigned phone number, serial number and PIN do. The fixed network unit receives the assigned telephone number on the ARM. Validity (39) is determined by the same assignment from the database of the fixed network unit. The determination is made by obtaining the telephone number (38). A call received from a subscriber unit. A comparison is made between the talk number and the valid numbers found in the database (39). be exposed.

If the assigned telephone number is not recognized by the fixed network unit, The authenticity certificate is denied (or some other action is taken) (40).

If the assigned phone number is determined to be valid (in the database) detected), the fixed network unit then retrieves that particular Retrieve the serial number and PIN corresponding to the assigned phone number.

The fixed network unit then retrieves the PIN from the database and the ARM The received data is transferred to the subscriber unit using the same Use as an encryption key as an element of the encryption method (44) and its own encryption Generates an encoded serial number. Fixed network units are encrypted with this The serial number is compared with the serial number encrypted by the subscriber unit (46). Compare. If they are not substantially the same, the system will deny access. or take some other predetermined action (47). If they are acceptable or acceptable If within the difference, the received call sequence count is obtained (48) and the fixed network The call count (50) is compared with the call count maintained by the network communication unit (49). ). If the counts are substantially the same, the authenticity is confirmed (52); This is the first predetermined course of action. In this case, the subscriber receives the dialed number is allowed to communicate with a third communication unit associated with the number. This third uni A requested resource is more commonly referred to as a requested communication resource. If said count is acceptable If not within reasonable tolerances, the certificate of authenticity will be denied or the authority will be notified that you are about to access the system (51 ).

A call counter in a fixed network unit records the number of times a certificate of authenticity has been accepted by a subscriber. maintain. Each subscriber has its own call counter. Subscribers and fixed networks Having a continuous call counting mechanism between the client and the prevents the thief from using the identification number of another subscriber. This is because the subscriber does not generate the same number of calls that it generated. This discrepancy is due to fixed net Flagged by the work unit when it compares two counts .

Protection against unauthorized users is further encrypted by encrypted dialing phone numbers and a PIN (which is not sent).

Correct algorithm for unauthorized users to encrypt subscriber PINs and serial numbers Without knowing the system, a thief can simply copy the subscriber's authentication message. limited to repeating messages. Subscriber dials different phone numbers A different authenticity request message is generated each time, and the reason for each request is different. If the subscribers have different PINs and each subscriber has a different authenticator for the same phone number. This is because a certification request message is generated.

The thief cannot detect the call request count because it is not encrypted in the ARM. ) and may update it, but only the correct count is the dark he stole. Allows obtaining proof of authenticity for encrypted dialing phone numbers. Therefore, it is unfair The user must enter an account whose encrypted phone number matches the one copied from the ARM. Can only communicate with registered users.

Another embodiment provides that the call sequence count is more than one call count for each subscriber. in this case for each fixed network communication unit. A separate call counter is required. This embodiment provides subscribers with multiple fixed network communications. is of importance in cellular communication systems that allow the use of communication units. . Yet another embodiment for the flowchart of FIG. The step of comparing (50) includes comparing encrypted serial numbers (46). must be done before the backup.

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Claims (10)

[Claims] 1. between a subscriber unit and a central communication unit in a wireless telephone communication system A method for authenticating and protecting a (a) the subscriber unit has a first ID and a target communications unit other than the central communications unit; (b) providing a terminal endpoint identifier that uniquely identifies the terminal; ) changing the first ID as a function of the terminal endpoint identifier; generating a modified first ID at the subscriber unit by: and and (c) transmitting said change from the subscriber unit to the central communication unit via a wireless communication link. at least one of the changed first ID and the terminal endpoint identifier; the step of transmitting the part; A subscriber unit and a central communication unit in a wireless telephone communication system comprising Authenticity and protection methods between. 2. (a) the subscriber unit maintains a historical non-discretionary value; (b) converting the historical non-discretionary value at the subscriber unit to the terminal; Historical non-committals modified by changing as a function of the endpoint identifier. an arbitrary value is generated, and (c) said modified historical non-discretionary value is communicated to the subscriber unit via a wireless communication link; sent from the unit to the central communication unit, A method according to claim 1. 3. The historical non-arbitrary value is a claim having a count of a predetermined number of communication events. The method described in Scope No. 2. 4. (a) said subscriber unit is provided with a second ID; and (b) the modified first ID is the same as the first ID in the subscriber unit; as a function of the terminal endpoint identifier and the second ID. generated by A method according to claim 1. 5. between a subscriber unit and a central communication unit in a wireless telephone communication system A method for authenticating and protecting a (a) providing a first ID to the central communication unit; (b) the first ID changed in the central communication unit and the central communication unit; A terminal endpoint identifier that uniquely identifies a target communication unit other than receiving at least a portion of the modified first ID; D and what is obtained from the terminal endpoint identifier, and (c) at the central communication unit, the received modified first ID; the received at least one portion of a terminal endpoint identifier and the first ID; A method for determining whether a received service request is genuine by using floor, A subscriber unit and a central communication unit in a wireless telephone communication system comprising Authenticity and protection methods between. 6. (a) the central communication unit maintains a historical non-arbitrary value; (b) said central communications unit is configured to have a modified historical record in said central communications unit; and (c) the received service request is genuine. The step of determining whether there is a (i) said received modified historical non-discretionary value information is substantially within said A history that is substantially the same as a historical non-discretionary value maintained by the central communications unit. said subscriber unit and said data if substantially derived from historical non-arbitrary values; target communication unit uniquely identified by the terminal endpoint identifier. a step of approving communications between; and (ii) said received modified historical non-discretionary value information is substantially A history that is materially different from the historical non-discretionary value maintained by the central communications unit. If multiple users receive said wireless telephone communication substantially from a non-arbitrary value, providing output indicating that the system is being accessed; 6. The method according to claim 5, comprising: 7. (a) a second ID is provided to said central communication unit; and (b) determining whether the received service request is for correction; 6. The method of claim 5, comprising the use of an ID of 2. 8. between a subscriber unit and a central communication unit in a wireless telephone communication system A method for authenticating and protecting a (a) providing said subscriber unit with a first ID and a target other than said central communications unit; A stage for providing a terminal endpoint identifier that uniquely identifies a communication unit. (b) providing the first ID to the central communication unit; (c) assigning the first ID to the terminal endpoint in the subscriber unit; generating a modified first ID by modifying the first ID as a function of the client identifier; (d) the modified first ID and the terminal via a wireless communication link; transfer at least a portion of the endpoint identifier from the subscriber unit to the central communications unit. the step of sending it to the (e) said changed first ID and terminal address in the central communication unit; receiving at least a portion of the endpoint identifier; (f) the received modified first ID, the terminal endpoint identification; By using the received at least a portion of the Bessenger and the first ID, the central communication Determine whether a service request received at the unit is genuine step, A subscriber unit and a central communication unit in a wireless telephone communication system comprising Authenticity and protection methods between. 9. (a) said subscriber unit and central communication unit are historical non-discretionary values; maintain, (b) the changed historical non-discretionary value is communicated to the subscriber unit via a wireless communication link; from the host to the central communication unit, (c) the central communications unit has a historical record of changes in the central communications unit; and (d) the received service request is genuine. The step of determining whether there is a (i) said received modified historical non-discretionary value information is substantially within said substantially the same as the historical non-discretionary value maintained by the central communications unit said subscriber unit and said terminal if obtained from historical non-arbitrary values. communication with the target communication unit, which is uniquely identified by the endpoint identifier. the step of approving the trust; and (ii) said received modified historical non-discretionary value information is substantially A history that differs materially from the historical non-arbitrary value maintained by the central communications unit. Multiple users can use a wireless telephone communication system when derived from historical non-arbitrary values. providing output indicating what you are trying to access; 9. The method according to claim 8, comprising: 10. (a) the subscriber unit is provided with a second ID; (b) said central communication unit is provided with said second ID; and (c) said changed a first ID that connects the first ID to a terminal endpoint in the subscriber unit; as a function of the int identifier and the second ID, and hand (d) determining whether the received service request is genuine; further comprising the use of said second ID; The method according to claim 8.