One-time logon method for distributed computing systems

[0001] The present invention relates to a login authentication technique that allows a user who is using a business system to use a commercial service system safely and enables multiple users who are using the business system to share an account of the commercial service system.

[0002] At present, a user frequently uses various commercial services via an intranet business system and the Internet at the same time. The intranet business system performs login authentication to enable processing in accordance with the user's official authority. However, if a service via the Internet is charged, the login authentication is required for utilization of the service. The following requirements are provided for utilization of these multiple systems.

[0003] (1) When a user uses a commercial service system from inside an enterprise, the user needs not to be aware of the system or service that the user is using. That is, the login authentication of the commercial service system needs not to be performed explicitly.

[0004] (2) Because in-house users who can use a commercial service system must be limited in accordance with their official authority, security concerning information (accounting) about login authentication needs also to be considered. That is, even if a password is leaked to another user, the password is rejected by the login authentication.

[0005] (3) Because a business system that is already operating and a commercial service may be linked, a load on the business system is minimized.

[0006] (4) Because it is mostly unrealistic from the standpoint of accounting that accounts for in-house users who use a commercial service are secured, multiple in-house users can share an account.

[0007] To satisfy the requirement (1), a method for transferring a special key generated in accordance with a protocol arranged between a business system and a service system to a client (terminal) is considered so that the commercial service can directly be used from the client. In this case, to satisfy the requirement (2), a fixed user ID and a password in the normal login authentication cannot be used as the key. To realize the above login authentication function, utilization of what is called a one-time password is considered. The prototype of the one-time password is a Lamport's Hash algorithm, and is described in Password Authentication with Insecure Communication by Leslie Lamport of Communications of the ACM, Volume 24, Issue 11 (November 1981), pages 770 to 772.

[0008] In a Lamport's hash algorithm, a password that will be used next is determined by inquiring an numerical value n that indicates how far the password was consumed and the service system side ought to store this n and only the corresponding hash value. However, there are the following two problems to apply this one-time password to the business system and the commercial service system.

[0009] The first problem is that because communication is performed between the business system and the service system in accordance with the Lamport's hash algorithm, the communication needs to be performed multiple times between the business system and the service system, thereby increasing the load of the business system.

[0010] The second problem is that only one hash value is stored at the service side and one account cannot be used by multiple persons at the same time.

[0011] An object of the present invention is to provide a login authentication method for reducing traffic and enabling concurrent utilization of one account by the multiple persons and its implementation system.

[0012] According to the method described in a first aspect of the present invention, because the communication that inquires how far a password has been used at present needs not to be performed, the traffic can be reduced. Further, according to the method described in claim 2 or 3, all passwords have previously been sent to the commercial service system, multiple persons can perform login processing at the same time.

[0013] FIG. 1 is a general drawing of a processing method according to one example of the present invention.

[0014] FIG. 2 is a block diagram of the password list of the present invention.

[0015] FIG. 3 is a general drawing of the processing method in the accounting information of the present invention.

[0016] One embodiment of the present invention is described below.

[0017] FIG. 1 shows a general drawing of a processing method according to one example of the present invention. In an enterprise, there are a business system 1 and a client 3 (terminal or computer) that a user uses. The user logs in the business system 1. Further, the user also uses a service system that exists in an external commercial service site. A commercial service system has accounting information 41 every user to manage the user. The case where multiple users share and use this accounting information 41 is considered.

[0018] Prior to login authentication, a password list 40 is generated in a business system. There are N passwords in this password list 40. Here, an individual password is assumed to be generated from a random number. This password list 40 is sent 500 to a service system 2 and stored in the password of the accounting information 41. Further, each password stores a pair of flags that indicate whether this password is already used or unused. The initial value of this flag is unused. When the user uses a commercial service, the user sends 501 a request for use of the commercial service system 2 from the client 3 that the user is using to the business system 1.

[0019] The business system 1 that received the request for use checks 502 a commercial service use authority of the user. If the use authority is provided, any password 401 is selected 503 from the password list 40 and returned 504 to a client.

[0020] To prevent that the selected password is allocated to a clients again, the selected password is eliminated from the password list or the line for the selected password is made blank.

[0021] The client 3 sends 505 the returned password to the commercial service system 2. The commercial service system 2 makes a comparison 506 with a password within the accounting information 41, and permits login if a matching password (411 in this case) is provided. Further, the commercial service system 2 changes a flag paired with the used password to the used flag in order to nullify 507 the used password.

[0022] In a series of processing described above, login authentication processing can be performed by multiple users to one account at the same time by always allocating a different password to each user.

[0023] The one embodiment was described above, but as a modification example of this example, an example when one-time password algorithm is modified and applied to a processing method of the present invention is described below.

[0024] A second example in which the password list 40 in a first example was replaced is described using the password list of FIG. 2. At this point, an individual password is generated by sequentially applying a hash function to an optional initial value r. Here, Hashn(r) 402 indicates the result in which the hash function is applied to r n times (402).

[0025] Prior to login authentication, a business system sends 500 the total applicable number of times N of the hash function and only HashN(r) to the service system 2.

[0026] A third example in which the accounting information 41 in the first example was replaced is described using the accounting information of FIG. 3. Here, each password stores the applicable number of times of the hash function and a pair of flags that indicate whether this password is already used or unused (412). In the initial state, the accounting information stores Hash N(r), N, and only unused pair of flags.

[0027] When a request for use of a commercial service is received from a user, the password selection processing 503 of the business system 1 allocates a password sequentially from the password of which the applicable number of times n is high.

[0028] The return processing 504 to a client also returns the password 402 and the applicable number of times n. The comparison processing 506 in the commercial service system 2 compares the result (Hash N-n(password) in which a hash function was applied to the password Hashn(r) sent from the client only for the part in which the applicable number of times n was subtracted from the total number of applicable times N and a numerical value of HashN(r), and permits login if they match.

[0029] An example for reducing computational complexity of a hash function in the commercial service system 2 is shown. Because the comparison processing 506 in the commercial service system 2 performs computation to which the hash function is applied multiple times, each intermediate result is added to the accounting information 41. Here, when the computation is performed until the applicable number of times is set to m, the computation of the hash function results in Hash mn(password) and the result is compared with Hash m(r). On this occasion, the intermediate result from the applicable number of times n to m is stored. Subsequently, in the compare processing of the password of which the applicable number of times is higher than n and lower than m, the hash function is not computed.

[0030] A user can use a business system and a commercial service system without needing to be aware of the system or service that the user is using.

[0031] A business limit indicating that Only a specific user can use a commercial service can be satisfied safely.

[0032] The traffic between the business system and the commercial service system can be reduced.

[0033] Further, one account of the commercial service system can be shared by multiple persons.

[0034] As a result, the traffic is reduced and the concurrent utilization of the one account by the multiple persons is enabled.