System and method for filtering data received by a computer system

• US 8,224,950 B2
• Filed: 02/19/2003
• Issued: 07/17/2012
• Est. Priority Date: 03/25/1997
• Status: Active Grant

• Current Assignee: Gen Digital Inc.
• Original Assignee: Symantec Corporation (NortonLifeLock Inc.)
• Inventors: Humes, Donald Creig
• Primary Examiner(s): WINDER, PATRICE L
• Application Number:
  US10/370,936
• Publication Number:
  US 20030140152A1
• Time in Patent Office: 3,436 Days
• Field of Search: 709/224, 709/225
• US Class Current: 709/224
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation
• CPC Class Codes: H04L 63/0236 Filtering by address, protocol, port number or service, e.g. IP-address or URL
• CPC Class Codes: H04L 63/0245 Filtering by information in the payload
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/102 Entity profiles
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The present invention provides a system and method for restricting access to data received by a computer over a network by filtering certain data from the data received. In a preferred embodiment, the present invention provides a computer based method for filtering objectionable or target text data from World Wide Web pages which are received by a computer system connected to the Internet. According to the method, if the web page requested by the user contains only a minimum of objectionable or target data, the user may receive a portion of the filtered web page for downloading and viewing on his or her computer. If the web page requested contains a large amount of objectionable or target data, the invention will cause a “forbidden” page to be displayed on the user'"'"'s computer monitor.

Claims

1. A method for filtering a requested web page, the requested web page having a Uniform Resource Locator (URL) portion, a header portion, and a body portion, the method comprising:

obtaining the URL portion of the requested web page;

filtering the URL portion to determine if access to the requested web page is denied based upon the URL portion;

determining if access to the requested web page is denied based upon the URL portion;

if it is determined that access to the requested web page is denied based upon the URL portion, providing an output indicating that access to the requested web page is denied;

if it is determined that access to the requested web page is not denied based upon the URL portion, determining if the requested web page is to be output based upon the URL portion;

if it is determined that the requested web page is to be output based upon the URL portion, obtaining the requested web page and providing an output of the requested web page;

if it is determined that the requested web page is not to be output based upon the URL portion, obtaining the header portion of the requested web page;

filtering the header portion to determine if access to the requested web page is denied based upon the header portion;

determining if access to the requested web page is denied based upon the header portion;

if it is determined that access to the requested web page is denied based upon the header portion, providing the output indicating that access to the requested web page is denied; and

if it is determined that access to the requested web page is not denied based upon the header portion, obtaining and filtering the body portion of the requested web page for target content.

2. The method of claim 1, wherein the filtering the body portion of the requested web page comprises:

obtaining at least a first portion of the body portion;

filtering the at least a first portion for instances of target content;

determining if the at least a first portion of the body portion is to be modified based upon the instances of the target content;

if the at least a first portion of the body portion is to be modified, modifying the at least a first portion to generate a modified at least a first portion and providing an output of the modified at least a first portion; and

if the at least a first portion of the body portion is not to be modified, providing an output of the at least a first portion.

3. The method of claim 2, wherein the method is implemented on a proxy server.

4. The method of claim 3, wherein the requested web page is input by a user on a host computer, the host computer being communicatively coupled to the proxy server, and further wherein at least one output selected from the group consisting of the output indicating that access to the requested web page is denied, the output of the requested web page, the output of the modified at least a first portion, and the output of the at least a first portion are communicated from the proxy server to the host computer.

5. The method of claim 1, wherein the filtering the URL portion to determine if access to the requested web page is denied based upon the URL portion comprises:

filtering the URL portion for one or more URL characteristics.

6. The method of claim 1, wherein the filtering the header portion to determine if access to the requested web page is denied based upon the header portion comprises:

filtering the header portion for one or more header characteristics.

7. A method for filtering a request to access a web page, the method comprising:

inputting a request to access a web page at a host computer;

communicating the request to a proxy server;

receiving the request at the proxy server;

filtering the request at the proxy server to determine if access to the web page is denied;

determining if access to the web page is denied;

if it is determined that access to the web page is denied, providing an output to the host computer indicating access to the web page is denied;

if it is determined that access to the web page is not denied, obtaining at least a portion of a header of the web page;

filtering the at least a portion of the header of the web page to determine if at least a portion of a body of the web page is to be filtered for instances of target content;

if it is determined that at least a portion of the body of the web page is to be filtered for instances of target content, obtaining the at least a portion of the body of the web page;

filtering the at least a portion of the body of the web page for instances of target content;

determining if the at least a portion of the body of the web page is to be modified based upon the instances of target content;

if it is determined that the at least a portion of the body of the web page is not to be modified, providing an output of the at least a portion of the body of the web page to the host computer;

if it is determined that the at least a portion of the body of the web page is to be modified, modifying the at least a portion of the body of the web page to generate a modified at least a portion of the body of the web page; and

outputting the modified at least a portion of the body of the web page to the host computer.

8. The method of claim 7, wherein the filtering the request at the proxy server to determine if access to the web page is denied comprises:

filtering the request at the proxy server for instances of one or more characteristics, and

further wherein the determining if access to the web page is denied is based upon the instances of one or more characteristics filtered in the request.

9. The method of claim 7, wherein the modifying the at least a portion of the body of the web page comprises replacing the instances of target content with substitute data.

10. The method of claim 9, wherein the substitute data is highlighted in the modified at least a portion of the body of the web page.

11. The method of claim 9, wherein the substitute data is one of one or more replacement words and one or more replacement symbols.

12. A method comprising:

receiving a request to access a web page, the request to access the web page including at least a URL portion, the web page including at least a header portion and a body portion;

filtering the request to access the web page to determine whether to deny access to the web page, approve access to the web page, or to filter the header portion of the web page;

determining whether to deny access to the web page, approve access to the web page, or to filter the header portion of the web page;

if it is determined to deny access to the web page, providing an output indicating access to the web page is denied;

if it is determined to approve access to the web page, providing an output of the web page;

if it is determined to filter the header portion of the web page, filtering the header portion of the web page to determine whether to filter the body portion of the web page; and

if it is determined to filter the body portion of the web page, filtering the body portion of the web page for target content.

13. The method of claim 12, wherein determining whether to deny access to the web page is based upon the URL.

14. The method of claim 12, wherein determining whether to approve access to the web page is based upon the URL.

15. The method of claim 12, wherein determining whether to filter the header portion of the web page is based upon the URL.

16. The method of claim 12, wherein after filtering the body portion of the web page for target content, determining whether to modify the body portion of the web page;

if it is determined not to modify the body portion of the web page, providing an output of the web page; and

if it is determined to modify the body portion of the web page, replacing the target content with substitute data to generate a modified body portion, and providing an output of the modified body portion.