JP2008021021A - License authentication method for software - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a software license authentication method capable of reliably preventing unauthorized use without notifying a licensor of computer specific information that may lead to privacy infringement.
A procedure in which a licensed computer restricts functions of installed software, a procedure for extracting computer-specific information capable of uniquely identifying the computer from hardware components of the licensed computer, A procedure 11 for randomly generating a session ID for each installation session, a procedure for encrypting computer-specific information using the session ID as a key (15) and storing it in the storage area 18 in the computer, and a session ID and serial number A software license authentication method including a procedure 12 for transmitting to a licensor and requesting issuance of a license key.
[Selection] Figure 1

Description

  The present invention relates to a software license authentication method for a computer such as a personal computer (PC), and more particularly, to a means for achieving both privacy protection and unauthorized copy prevention when authenticating a license.

  Conventionally, an authentication method in which a license key provided by a licensor is input to an installation program and the installation program checks the validity of the key has been common.

  However, once a license key is issued, it cannot be managed on the licensor side and can be used without limitation. As a result, there has been a problem that the software can be easily installed on more computers than the contract number.

  There is also a method in which a license key is provided as a hardware device and the license information in the hardware device is checked and authenticated each time the software is used.

  However, the cost is high and there is a restriction that an interface for connecting a hardware device is required on the computer side, so that it has not spread widely.

  Therefore, a method for authenticating a license using computer-specific information has been proposed. Prior to installation, computer-specific information to be installed (for example, information having a unique value for each computer such as computer hardware information and IP address) and a serial number attached to the software are transmitted to the licensor. The licensor verifies whether the serial number is valid, and if there is no problem, returns an activation code in which the license key is encrypted using the computer-specific information as a key. When the activation code is input to the installation program, if the computer is a legitimate computer, the license key can be decrypted with its own computer-specific information, and the software installation operation is completed.

  According to this method, even when the entire files constituting the computer software are copied to another computer, the license is authenticated by trying to decrypt the license key every time the software is activated, so that unauthorized use can be prevented. In addition, a pair of serial number and computer-specific information is managed on the licensor side, and re-issuance of an activation code using the serial number can be prevented.

  The activation code issuance method includes a method using a license authentication server (see, for example, Patent Document 1) and a method in which an IC card has an activation code issuing function and a computer-specific information holding function (for example, a patent). Document 2) has been proposed.

  As a method for preventing unauthorized installation of the license server itself, a method has been proposed in which a server certificate is issued at the root server and authentication is required at the root server when issuing an activation code (see, for example, Patent Document 3). ).

  ID information unique to the user's computer, such as the OS's original number, hard disk manufacturing number, and MAC address of the network card, is obtained to generate the user machine ID and notification ID, and notifies the licensor. The licensor issues an authentication password. Has been proposed (see, for example, Patent Document 4).

Japanese Unexamined Patent Publication No. 2000-207199 (pages 4-5) Japanese Patent Laying-Open No. 2005-122283 (pages 8 to 10 and FIGS. 3 and 4) JP 2004-206435 A (pages 8 to 11 FIGS. 1 to 6) Japanese Patent Application Laid-Open No. 2004-171500 (pages 3 to 4 and FIGS. 1 to 4)

  In the method of Patent Document 1, it is necessary to communicate the computer-specific information to the licensor, and there is a sense of resistance for the user from the viewpoint of privacy protection. In addition, the activation code issuance procedure must be taken for all the computers that authenticate the license, which is troublesome. In order to reduce this effort, there is a method of installing a local license authentication server having a function of issuing an activation code on the customer site side.

  However, this method generates server installation costs and management costs. Furthermore, it is not possible to prevent unauthorized installation of the server itself.

  In the method of Patent Document 2, a special hardware device and its connection interface are required for the computer, which increases costs.

  In the method of Patent Document 3, fraud cannot be detected when a digital certificate is copied, for example, when the entire HDD image is copied to another server.

  In the method of Patent Document 4, when sending the notification ID, other information such as the user name, residence, telephone number, date of birth, age, and occupation is also sent, and the licensor gives the authentication password to the user. It is possible to create a database of user information as well as issuing With this method, user information is stored at the hands of third parties, which not only goes against the recent trend toward privacy protection, but also for licensors in the case of confidentiality of the information and compensation in case of leakage. It requires a great deal of labor and expense.

  Furthermore, the activation code issuance request is required for the number of computers for which a license agreement has been made, and hardware specific information on the total number of computers must be notified to the licensor.

  A first object of the present invention is to provide a software license authentication method capable of reliably preventing unauthorized use without contacting a licensor with computer-specific information that may lead to privacy infringement.

  A second object of the present invention is to provide a software license authentication method that can reliably prevent unauthorized use in a plurality of computers without contacting all of the computer-specific information relating to the plurality of computers to a licensor. That is.

  In order to solve the first problem, the present invention provides a computer in which a licensed computer can uniquely identify a computer from a procedure for restricting functions of installed software and hardware components of the computer. A procedure for extracting unique information, a procedure for randomly generating a session ID for each installation session, a procedure for encrypting and storing the computer unique information using a session ID as a key, and a session ID, A software license authentication method including a procedure for transmitting a serial number to a licensor and requesting issuance of a license key is proposed.

  In order to solve the second problem, the present invention provides a procedure in which a plurality of license-target computers connected to each other restrict the functions of software installed in each of the computers, and the hardware components of the computer A procedure for extracting computer-specific information that can uniquely identify a computer, a procedure for accepting input of a session ID of another computer connected before the generation of its own session ID, and a session for each installation session A procedure for randomly generating an ID; a procedure for encrypting the computer-specific information using the session ID of the user as a key; and storing the information in a storage area in the computer; and sending the session ID and serial number of the user to the licensor. And a procedure for requesting the issuance of The licensor has a license management database for registering and managing a serial number and a session ID as a pair, and a license key for releasing the restriction of the software function in response to a request for issuing a license key for an unregistered serial number. Including a step of generating an activation code by encrypting with a session ID of the last computer among a plurality of licensed computers, and a step of transmitting the activation code to the last computer, wherein the last computer is encrypted A procedure for decrypting the session ID stored in the storage area in the computer with the computer-specific information, a procedure for determining that the session ID has been illegally copied if the decryption of the session ID has failed, and a session for successful decryption of the session ID. The procedure for decrypting the license key from the activation code with the license ID, the procedure for determining that an illegal license key was used if the decryption of the license key failed, and the authorized computer if the decryption of the license key was successful A plurality of licensed computers connected to each other, the licensed computer immediately before the license of the last computer is authenticated. We propose a software license authentication method that includes the steps of issuing the activation codes in reverse order and repeating the license authentication.

  In the present invention, when a license is granted, a verification key for identifying a computer individual is separated from the computer specific information, and the computer specific information is required to use the verification key. At the time of licensing, a verification key is transmitted without exchanging computer-specific information which is a problem for privacy protection. In the present invention, a unique session ID is generated and used for each installation session as the verification key.

  Here, the installation session refers to a series of actions from installing software to a computer and activating the function. Even if the same software is installed on the same computer, if the installation is temporarily stopped and then restarted or reinstalled, since the actions are not a series, they are regarded as different sessions.

  In the computer where the software is installed, a session ID is generated by the installation program. Since the session ID is encrypted by the computer specific information and stored in the storage area of the computer, even if the entire software including the encrypted session ID is copied to another computer, the session ID is copied on the copy destination computer. Thus, the uniqueness of the computer that continues the session is ensured.

  The installation program transmits the generated session ID and serial number to the licensor in order to request issuance of an activation code. It may be automatically transmitted from the installation program via the network, or may be transferred by fax and e-mail.

  The licensor that has received the session ID and serial number checks whether or not the received serial number has been registered in the license database. If the registered serial number is illegally used to request the issuance of a license key, it is possible to prevent duplicate issuance of license keys.

  If the serial number is not registered, the serial number and session ID pair is registered in the license management database, and the license key is encrypted with the session ID to generate an activation code. The activation code may be sent directly to the installation program via a network, or may be transferred to a fax or e-mail.

  In the license target computer, the license key is decrypted from the activation code based on the session ID. Therefore, the license code cannot be acquired by a computer that does not have a regular session ID, and unauthorized use of the activation code can be prevented.

  The license key is re-encrypted with the computer-specific information and stored in a storage area in the license target computer.

  To start the software, it is necessary to decrypt the license key based on the computer specific information. Therefore, even if the entire software including the license key information is illegally copied from the activated computer, the license key cannot be decrypted, and unauthorized use can be prevented.

  In the present invention, when installing on a plurality of computers, session IDs are generated in a chain. The activation issuance request may be transmitted only by the final computer, and upon completion of license authentication of the final computer, the other computers are also serially authenticated for licenses in the reverse order of the session ID generation. The final installation number is included in the session ID, and the licensor can check the number of licenses against the actual number of installations. Since only one other activation code can be issued per computer, license authentication is not obtained for computers that are out of the chain, and unauthorized installation can be prevented.

  It is also assumed that a malicious third party attempts to issue an activation code with an appropriate pair of serial number and session ID, and happens to input a valid serial number. In this case, in the present invention, the message ID of the serial number can also be included in the session ID, and it can be verified whether the session ID is generated by a regular procedure by the installation program. This will not prevent the activation code from being issued by the authorized serial number holder.

  According to the present invention, unauthorized installation due to diversion of a serial number and an activation code can be prevented. Even if software is illegally copied from a licensed computer, its use can be blocked. When implementing these defense functions, it is not necessary to provide computer-specific information to the licensor, and the user's privacy is protected.

  Further, when installing on a plurality of computers, only one activation code issuance procedure is required, and the troublesomeness is reduced.

  Next, an embodiment of the software license authentication method according to the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a system configuration of a license authentication system for authenticating a license to one computer according to the present invention.

  The license authentication system according to the first embodiment includes a license target computer 10 on which software is installed and an activation code issuing server 20, which are connected via a network 50. The license target computer 10 is not limited to the personal computer PC but may be a workstation or a server.

  At the time of installation, a recording medium 30 in which the installation program and the license target application program are recorded, and a serial number 40 attached to the recording medium 30 and provided from the licensor are required.

  The license target computer 10 includes a session ID generation unit 11, an issue request unit 12 that requests the activation code issue server 20 to issue an activation code, a license key decryption unit 13, a license key verification unit 14, and an encryption unit. 15, a decryption unit 16, a PC specific information extraction unit 17, an HDD 18, and a storage unit for the installed application program 19.

  The application code issuance server 20 includes an issuance acceptance unit 21 that accepts a license key issuance request, a serial key registration verification unit 22, a license key encryption unit 23, and a license management database 24 that registers a serial number and a session ID in pairs. Including.

  Next, an example of a procedure for installing an application program in the license target computer 10, receiving license authentication, and validating the licensed application program will be described.

  FIG. 2 is a flowchart illustrating a processing procedure in which the license target computer 10 requests the activation code to be issued.

  The application program user starts the installation program from the recording medium 30 (S100). When the serial number is input according to the instruction of the installation program (S101), the modules constituting the application program 19 are copied from the recording medium 30 to the license target computer 10 (S102).

  If it is necessary to change the system file of the license target computer 10 for the operation of the application program 19, the change is also performed. In the first embodiment, the installation program and the application program are provided on the recording medium 30. However, the installation program and the application program may be downloaded via a network.

  The session ID generation unit 11 generates a session ID as a unique code for each installation session (S103). In order to generate a unique session ID in this way, there is a method of generating a code by combining the time of installation start and the message digest of the serial number and encrypting it using a secret key built in the installation program 19. Since the system time of the computer has a resolution of about millisecond, a sufficiently unique session ID can be generated as compared with the time scale required for installation work.

  A message digest is a fixed-length pseudo-random number sequence that is generated from a source text using a predetermined algorithm. Since the source text cannot be reproduced irreversibly, it has the property that it is impossible to find two source texts that generate the same message digest. . Such algorithms include MD5 and SHA.

  The computer specific extraction information unit 17 extracts computer specific information and sets it as computer specific extraction information (S104). As the computer unique extraction information, a unique identification number assigned to a part constituting the computer, such as a MAC address or a processor code of an Ethernet (registered trademark) LAN interface, can be used.

  The encryption unit 15 encrypts the session ID using the computer-specific extraction information as a key. The resulting cipher is stored in the HDD 18 in the license target computer 10 (S105).

  The issue request unit 12 transmits the serial number and the session ID to the activation code issue server 20 via the network 50, and requests the activation code to be issued (S106).

  Depending on the function of the installation program, unlike the present embodiment, which directly communicates with the activation code issuing server 20, a use state where the license target computer 10 cannot be connected to the network 50 is also assumed. In this case, the session ID may be displayed on the display of the license target computer 10, and the user may notify the licensor using means such as e-mail, FAX, or telephone.

  Further, the activation code issuing server 20 may be disclosed as a Web server on the Internet, and may be requested to issue an activation code by inputting a session ID and a license number from a Web screen.

  FIG. 3 is a flowchart illustrating an example of a processing procedure of the activation code issuing server 20.

  The activation code issuing server 20 receives the serial number and the session ID (S201). The serial key registration collation unit 22 of the activation code issuing server 20 checks whether or not the serial number and the session ID are already registered in the license management DB 24 (S202). If the session ID has already been registered, it is determined that the serial number has been misappropriated (S203), and the activation code issuance process is interrupted (S205). In this case, a message is transmitted to the license target computer 10 via the network 50 to notify the user that it is illegally diverted.

  If the session ID is unregistered, the serial key registration / collation unit 22 of the activation code issuing server 20 estimates that the request is valid for issuing the activation code (S203), and the serial number and session ID are stored in the license management DB 24. Are registered in pairs (S204).

  The license key encryption unit 23 of the activation code issuing server 20 encrypts the license key for canceling the function suppression of the application program using the session ID as a key, and generates an activation code (S206). The generated activation code is transmitted to the license target computer 10 via the network 50 (S207).

  In the first embodiment, the activation code is directly communicated with the installation program of the license target computer 10 and the activation code is notified. However, the notification may be made by e-mail or FAX. When an issuance request is received from the Web screen, an activation code may be displayed on the Web screen.

  FIG. 4 is a flowchart showing the activation procedure of the application program in the license target computer 10. Upon receiving the activation code (S111), the license target computer 10 extracts computer specific information (S112). Subsequently, the session ID 181 encrypted and stored in the HDD 18 is read, and the session ID is decrypted using the computer-specific information as a key (S113). If decryption of the session ID fails (S104), the activation process is interrupted (S116).

  Even if the encrypted session ID is illegally copied, since the computer-specific information is different and the session ID cannot be decrypted unless the computer originally generated the session ID, the activation can be prevented from continuing.

  When the session ID is successfully decrypted (S104), the license key is decrypted from the activation code using the decrypted session ID as a key (S116). If the decryption of the license key fails (S107), the activation process is interrupted. Even if the activation code is obtained illegally, the license key cannot be obtained because the session ID serving as the encryption key is different. Therefore, unauthorized use of the activation code can be prevented.

  If the decryption is successful (S107), the obtained license key is encrypted again using the computer specific information as a key and stored in the HDD 18.

  FIG. 5 is a flowchart showing a license authentication procedure in the license target computer 10.

  When the user activates the application program 19 (S121), computer-specific information is extracted (S122), and the encrypted license key 182 is decrypted (S123). If the decryption of the license key 182 fails (S124), the process is interrupted (S125).

  The first cause of the decryption failure is that the activation process has not been completed and the license key does not exist. In the case of the first cause, guidance for prompting to obtain a license key is displayed.

  The second cause of the decryption failure is that the license key is illegally copied from the computer that has been activated. In the case of the second cause, decryption fails because the computer-specific information that is the encryption key is different.

  If the decryption is successful (S124), the restriction on the suppressed function of the application program 19 is released.

  As a function restriction and its release method, for example, there is a method of embedding a license key in an execution code of an application program and collating it in the program.

  In addition, there is a method in which some execution modules and definition files necessary for application program operation are encrypted in advance with a license key, and decrypted with the license key obtained when the program is executed.

  FIG. 6 is a block diagram showing a system configuration of a license authentication system for authenticating licenses to a plurality of computers according to the present invention.

  The license authentication system according to the second embodiment includes a license target computer 10 on which software is installed and an activation code issuing server 20, which are connected via a network 50. There are N licensed computers 10, PC1 to PCN, which are connected to each other. The license target computer 10 is not limited to the personal computer PC but may be a workstation or a server.

  During installation, a so-called volume license version installation program that can be installed on a plurality of computers and a recording medium 30 on which a license target application program is recorded, and a serial number 40 attached to the recording medium 30 and provided by a licensor are required. become.

  The PCs 1 to PCN that are the individual license target computers 10 are the same as in the first embodiment, and include a session ID generation unit 11, an issue request unit 12 that requests the activation code issue server 20 to issue an activation code, and a license key. The decryption unit 13, the license key collation unit 14, the encryption unit 15, the decryption unit 16, the PC specific information extraction unit 17, the HDD 18, and a storage unit for the installed application program 19 are included.

  Similarly to the first embodiment, the application code issuance server 20 also includes an issuance acceptance unit 21 that accepts a license key issuance request, a serial key registration verification unit 22, a license key encryption unit 23, a serial number, and a session ID. And the license management database 24 to be registered.

  Next, an example of a procedure for installing an application program on a plurality of license target computers 10, receiving license authentication, and validating the licensed application program will be described.

  The first license target computer PC1 generates a session ID S1 and inputs it to the license target computer PC2. The cumulative installation number 1 is added to S1 of the session ID. Subsequently, a session ID S2 corresponding to the license target computer PC2 is generated. As a result of adding 1 to the cumulative installation number of the session ID S1, 2 is added to the session ID S2.

  In this manner, session ID input and generation are sequentially repeated up to the license target computer PCN, and finally the SN of the session ID corresponding to the license target computer PCN is obtained. A serial number and the cumulative installed number N are added to the session ID SN.

  When the license target computer PCN transmits the SN of the session ID to the activation code issuing server 20 of the licensor, the activation code issuing server 20 can grasp the number of license target computers at the customer site. The activation code issuing server 20 issues an activation code AN for the license target computer PCN if the number is within the limit of the number of contract licenses.

  The user inputs the activation code AN to the license target computer N and receives the license authentication. If the license target computer PCN is valid and the license authentication is successful, the installer of the license target computer PCN issues an activation code AN-1 of the license target computer PCN-1, and the license of the license target computer PCN-1 is issued. Authenticate.

  This procedure is repeated, and the licenses are authenticated up to the license target computer PCN-1, license target computers PCN-2, PCN-3,..., License target computer 1 in the reverse order to when the session ID is generated. Since the activation code is issued to only one computer for each license target computer, it is possible to prevent installation on a computer leaked from the session ID chain.

  According to the second embodiment, when viewed from the activation code issuing server 20 side, the license can be authenticated to a plurality of computers within the limit of the number of contract licenses by only activating one license target computer.

It is a block diagram which shows the system | strain structure of the license authentication system which authenticates a license to one computer by this invention. It is a flowchart which shows the process sequence in which the license object computer 10 requests | requires issue of an activation code. 4 is a flowchart illustrating an example of a processing procedure of an activation code issuing server 20. 4 is a flowchart showing an activation procedure of an application program in the license target computer 10. 4 is a flowchart showing a license authentication procedure in the license target computer 10. 1 is a block diagram showing a system configuration of a license authentication system that authenticates licenses to a plurality of computers according to the present invention. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 License object computer 11 Session ID generation part 12 Activation code issue request part 13 License key decryption part 14 License key collation part 15 Encryption part 16 Decryption part 17 PC specific information extraction part 18 HDD
181 Session ID
182 License Key 19 Application Program 20 Activation Code Issuing Server 21 Issuance Accepting Unit 22 Serial Key Registration / Verification Unit 23 License Key Encryption Unit 24 License Management Database 30 Recording Medium 40 Serial Number
50 network

Claims (9)

The licensed computer restricts the functionality of the installed software;
A procedure for extracting computer-specific information capable of uniquely identifying the computer from hardware components of the computer;
A procedure for randomly generating a session ID for each installation session;
A procedure for encrypting the computer-specific information using a session ID as a key and storing it in a storage area in the computer;
A software license authentication method comprising: a procedure of transmitting a session ID and a serial number to a licensor and requesting issuance of a license key. The software license authentication method according to claim 1,
The licensor has a license management database for registering and managing a serial number and a session ID as a pair;
A procedure for generating an activation code by encrypting a license key for releasing a restriction on software functions in response to a request for issuing a license key for an unregistered serial number with a session ID;
And a software license authentication method comprising: a step of transmitting an activation code to the licensed computer. In the software license authentication method according to claim 1 or 2,
The license target computer decrypts the encrypted session ID stored in the storage area in the computer with computer specific information;
A procedure for determining that the copy was illegal if the session ID could not be decrypted;
If the session ID is successfully decrypted, a procedure for decrypting the license key from the activation code with the session ID;
A procedure for determining that an invalid license key has been used when decryption of the license key fails,
A software license authentication method comprising: a step of determining that the activation is performed on a legitimate computer when the license key is successfully decrypted, and releasing the restriction on the function of the software. The software license authentication method according to claim 3,
The licensed computer encrypts the decrypted license key with computer specific information and stores it in a storage area in the computer;
A procedure for decrypting the license key with computer-specific information when using the software;
A software license authentication method, comprising: a step of determining that an illegal copy has been made if the license key decryption has failed and suppressing the function of the software. The licensed computer restricts the function of the installed software, extracts the computer-specific information that can uniquely identify the computer from the hardware components of the computer, and the session ID for each installation session A procedure for randomly generating a password, a procedure for encrypting the computer-specific information using a session ID as a key and storing it in a storage area in the computer, and sending the session ID and serial number to a licensor to request the issuance of a license key Including
The licensor has a license management database for registering and managing a serial number and a session ID as a pair, and in response to a license key issuance request for an unregistered serial number, a license key for releasing a restriction on software functions Including a procedure for generating an activation code by encrypting with an ID, and a procedure for transmitting the activation code to the licensed computer,
A procedure in which the licensed computer decrypts the session ID encrypted and stored in a storage area in the computer with computer-specific information; a procedure for determining that the session ID has been illegally copied if the session ID fails to be decrypted; If the decryption of the ID is successful, the procedure for decrypting the license key from the activation code with the session ID; if the decryption of the license key fails, the procedure for determining that an invalid license key has been used; and the decryption of the license key If it is successful, it is determined that the activation is a legitimate computer, and the procedure for releasing the restriction of the software function is included.
The license-target computer encrypts the decrypted license key with computer-specific information and saves it in a storage area in the computer, decrypts the license key with the computer-specific information when using the software, and decrypts the license key A software license authentication method, comprising: a step of determining that the software has been illegally copied in the case of failure, and suppressing a function of the software. A procedure in which a plurality of licensed computers connected to each other restricts the function of software installed in each of the computers; and a procedure for extracting computer-specific information capable of uniquely identifying the computer from hardware components of the computer; The procedure for accepting the input of the session ID of another computer connected before the generation of its own session ID, the procedure for randomly generating its own session ID for each installation session, and the key for its own session ID A procedure for encrypting the computer-specific information and storing it in a storage area in the computer, and a procedure for requesting the issuance of a license key by transmitting its own session ID and serial number to a licensor,
The licensor has a license management database for registering and managing a serial number and a session ID as a pair, and a license key for releasing a restriction on software functions in response to a request for issuing a license key for an unregistered serial number. Including a step of generating an activation code by encrypting with a session ID of the last computer among a plurality of licensed computers, and a step of transmitting the activation code to the last computer,
A procedure for the last computer to decrypt the encrypted session ID stored in the storage area of the computer with computer-specific information; a procedure for determining that the session ID is illegally copied if the session ID fails to be decrypted; If the decryption of the ID is successful, the procedure for decrypting the license key from the activation code with the session ID; if the decryption of the license key fails, the procedure for determining that an invalid license key has been used; and the decryption of the license key If it is successful, it is determined that the activation is a legitimate computer, and the procedure for releasing the restriction of the software function is included.
A plurality of licensed computers connected to each other, wherein when the license of the last computer is authenticated, the activation code of the licensed computer immediately before is issued in reverse order and the license authentication is repeated. License authentication method. The software license authentication method according to claim 6,
In addition to the information of claim 6, the session ID of each license target computer includes information on the cumulative number of installed machines,
A software license authentication method, characterized in that a cumulative installation number included in a session ID of a computer connected before that is extracted, 1 is added, and the addition result is added to a session ID generated by itself. The software license authentication method according to claim 6 or 7,
The licensed computer encrypts the decrypted license key with computer specific information and stores it in a storage area in the computer;
A procedure for decrypting the license key with computer-specific information when using the software;
A software license authentication method, comprising: a step of determining that an illegal copy has been made if the license key decryption has failed and suppressing the function of the software. The software license authentication method according to any one of claims 1 to 8,
A software license authentication method, wherein the session ID includes a serial number message digest.

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