KR100844742B1 - Reputation Management Method for Reliable Peer to Peer Services - Google Patents

Abstract

The present invention relates to a method for managing user reputation for reliability of a peer-to-peer service and a method for managing reputation information referred to for trust of users. The present invention permits a download request by comparing a trust value calculated using a good reputation and a bad reputation among users participating in a peer-to-peer file sharing service. Can improve. It can also reduce service participation for free riders and malicious users who only use resources of other users without sharing their resources.

Peer-to-peer file sharing reputation trust management free rider

Description

Reputation Management Method for Reliable Peer to Peer Services}

1 is a flowchart of the overall operation of the present invention.

2: Flowchart for file provider selection and download task

The present invention relates to a user reputation management method for the reliability of the peer-to-peer service, so that the service provider or requester can use the file sharing service based on mutual trust by referring to the reputation information of the service participants, and includes a virus or a worm. Restrict participation in services to users with malicious purposes to share files or free riders who only use them without sharing their resources and provide fairness to the use of services to participants. Peer-to-peer service, which has emerged as an alternative to the existing client / server method, performs a transaction through direct connection between the participants while the service participants operate as servers or clients according to the situation without a separate central server. Participants in most peer-to-peer services operate in different environments and do not place any special restrictions on their use of the service, allowing anyone to freely access and terminate the service, and to monitor or manage network activity. There is no user responsible. Therefore, some users favor service provision, but some users use only services provided by other users without providing services at all, or frequently provide wrong services to guarantee the quality of services provided by users. There is a problem that cannot be done and cannot guarantee the reliability of the service participants.

The present invention has been made to solve the above problems, and aims to provide trust to transaction participants and to ensure quality of service by referring to a trust value calculated using reputation information for users. It is still another object of the present invention to restrict the participation of the service to users or free riders with malicious purposes by granting download rights by comparing the trust values calculated using the good and bad reputation of participants.

The present invention relates to a method for managing user reputation for reliability of peer-to-peer services, and to a method for managing reputation information by referring to reputation information for trust of users. In operation, shared resources mean digital content (eg, text, video, sound, image files), and reputation and trust values for service participants are managed by the server. Participants' initial reputation and trust values can be specified differently depending on the application used. There is no limit on the maximum and minimum values. Messages between service participants are transmitted using a secure and confidential channel. In order to manage user reputation, the present invention includes the steps of login and registration; search request and response; selection and download; evaluation and update.

1. Login and Registration

Users who want to use the service log in to the server, and after confirming that the server is the correct user, the server sends a message indicating that the login is normal. Users who receive the response message from the server register the list of files to share with the server, and the server stores the following information for each user in a database that is easy to search, and the list is updated whenever a new peer connects. .

<P _x , f _i ... f _n , r _x , GR _x , BR _x , TP _x >

-P _x : Peer ID

-f _i ... f _n :: List of shared files

r _x : Evaluation value received as a result of transaction execution

-GR _x : Sum of peer's good reputation

-BR _x : Sum of bad reputation of peer

-TP _x : Calculated peer trust value based on good and bad reputation

2. Search request and response

Users request a search for the file from the server to get the file they need. The server receiving the search request transmits the user list and the trust value for the user based on whether the users who have a file matching the user's request in the stored list are connected.

3. Select and download

The file requestor selects a target for download by referring to the trust values of the file providers in the information received from the server, and requests the server for information necessary for connection to request the file download from the user. The server transmits information necessary for connection such as the file provider's IP address and port number, and the file requestor requests the file provider to download by referring to the information received from the server. The file provider compares itself with the file requestor's trust value before responding to the request, and sends the request file if the file requestor's trust value is greater than or equal to its trust value, and the file requestor's trust value is its trust value. If it is smaller, it sends a message indicating that the file could not be sent. Users can be authorized to download files based on their trust values, so if a user provides a wrong file for malicious purposes or a free rider, most download requests are rejected due to low trust values, so a small amount of The use of resources may be allowed, or the transaction itself may be rejected due to lack of trust. In order to increase their trust value, users need not only to share the right file but also to have a balanced participation in upload and download transactions.

4. Rate and Update

In case the file requester does not send an evaluation value for the file of the file provider after the transaction is terminated, the file provider notifies the server that the file requester and the transaction are terminated when the download is completed. The file requestor executes the file received from the file provider, verifies it, and sends an evaluation of the file to the server. If the downloaded file is working normally and matches the file requested by the user, it sends 1 as the evaluation value, otherwise it sends -1 as the evaluation value. After the server receives a message from the file provider indicating that the transaction with the file requester has ended, the server does not send an evaluation value for the file provider until the file requestor requests a query to perform a new transaction, or use the service without transmitting the evaluation value. Ending the file increases the bad reputation of the file requestor and sets the file provider's evaluation value to 0 for the currently executed transaction. The server receives the evaluation value for the file provider from the file requester, and updates the good and bad reputation and trust values of the file requestor and the file provider. The reputation of the file provider is divided into four methods according to the evaluation values received from the most recent transaction and the currently executed transaction.

Previous Now GR BR r _old = 1 r _new = 1 GR _old + | r _new | * a BR _old r _old = 1 r _new = -1 GR _old BR _old + | r _new | r _old = -1 r _new = 1 GR _old + | r _new | BR _old r _old = -1 r _new = -1 GR _old BR _old + | r _new | * a

If the file provider received a good rating both in the most recent transaction and in the current transaction, the good reputation is increased by a plus the previous value, and the bad reputation retains the previous value. If the file serving peer has a bad rating in both the most recent transaction and the current one, it increases the bad reputation by a plus the previous value, and the good reputation retains the previous value. If different evaluations are made in the most recent transaction and in the current transaction, the reputation is calculated according to the evaluation value received as a result of the current transaction. In other words, good reputation increases good reputation, bad reputation keeps old value, bad rating increases bad reputation, and good reputation keeps old value. By using such an update method, a good reputation of a user who is continuously receiving a good rating gradually increases, and a bad reputation of a user who is continuously receiving a bad rating gradually increases.

The value a is used to update the file provider and requestor's reputation and is used to weight the transaction participants as a percentage of the number of files shared by users. You can use the value of a to provide a lot of resources of your own and to provide incentives to users who receive good ratings for each transaction because the provided resources work correctly.

a = fn _old / fn _new

fn _new indicates the number of shared files a user has after executing a transaction. fn _old indicates the number of shared files the user has before executing a transaction. Generally, the number of shared files of a file provider when upload and download transactions occur between users. Does not change, but the number of files shared by the file requestor increases, but in theory, the number of files shared by the file provider decreases and the number of files shared by the file requestor increases. Using this principle, the value of a of the file provider is increased and the value of a of the file requestor is decreased by calculating the ratio of users to the number of shared files.

The file requester's reputation is updated by distinguishing the case where the evaluation value for the downloaded file is not transmitted. The update expression for the case where the evaluation value is transmitted is as follows.

GR _new = GR _old * a

Reducing good reputation to provide fairness to the file provider and requester's use of the service, such as restricting the user from continuously performing only download transactions and giving extra points to the user who performed the upload transaction.

If no evaluation value is sent, the following equation can be used to increase the bad reputation of the file requestor.

BR _new = BR _old * a

Based on the good and bad reputation of the updated users, the trust value of the user who refers to the transaction target is calculated as follows.

T = (GR _new- | BR _new | / BR _new + BR _new ) * b

If the file provider receives a good rating in subsequent transactions, the trust value increases with the increase of the good reputation, and if the bad provider receives a bad rating, the trust value decreases with the increase of the bad reputation. Service participants refer to the trust values of users calculated using good and bad reputation to select a transaction target, and the file provider compares the trust value of the file requestor with himself to grant the download request.

The present invention can improve the reliability of the transaction participant and the shared resources by allowing the download request through the comparison of the trust value calculated by referring to the good reputation and the bad reputation given by the users participating in the peer-to-peer file sharing service. . It can also limit the participation of free riders and users with malicious purposes who only use other users' resources without sharing their resources.

Claims (3)

In peer-to-peer services, you can use file sharing services based on mutual trust, ensure the quality of service, and share files including viruses or worms by referring to reputation information indicating trust in file providers and file requesters. In the method of managing reputation information to provide fairness in using the service by restricting participation in the service to file providers having malicious purposes or free riders who only download shared files. (a) Logging in and registering a shared file list registration on a central server by a file provider and file requester wishing to use a file sharing service, where the central server is the sum of each user's reputation, shared file list, good reputation, bad reputation, Steps to Database and Store Trust Values (b) requesting a search by the file requester to the central server to download the file, the central server checking the connection status of the file providers and sending the file provider list and trust value; (c) checking, by the file requester, the trust value of the file provider, selecting the file to download and requesting the file; (d) execute the file downloaded by the file requestor to verify it, and send the evaluation value for the file to the central server, and the server divides the file provider's reputation and trust value into two groups according to the evaluation value. Calculating and calculating the file requestor's reputation and trust value according to the transmission of the evaluation value by the file requestor. User reputation management method comprising the The method of claim 1, wherein the shared file ratio is used to incentivize users when calculating a user's trust value. The method of claim 1, wherein the user reputation management method permits a download request by comparing a trust value to limit the participation of the service to users or free riders who share files including viruses or worms for malicious purposes.

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