Digital data authentication method

• US 6,131,162 A
• Filed: 06/04/1998
• Issued: 10/10/2000
• Est. Priority Date: 06/05/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yoshiura, Hiroshi, Saito, Tsukasa, Takaragi, Kazuo, Toyoshima, Hisashi, Susaki, Seiichi, Sasaki, Ryoichi
• Primary Examiner(s): Swann, Tod R.
• Assistant Examiner(s): Darrow, Justin T.
• Application Number:
  US09/090,419
• Time in Patent Office: 859 Days
• Field of Search: 380/30, 380/28, 380/202, 380/279, 380/283, 705/51-58, 713/150, 713/155, 713/162, 713/168, 713/170, 713/176, 713/180, 713/181
• US Class Current: 713/176
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 2201/0063 in relation to collusion attacks, e.g. collusion attack resistant
• CPC Class Codes: G06T 2201/0081 whereby both original and watermarked images are required at decoder, e.g. destination-based, non-blind, non-oblivious
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2463/103 applying security measure for protecting copyright
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04L 9/08 Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords network architectures or network communication protocols for supporting key management in a packet data network H04L63/06
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/42684 Client identification by a unique number or address, e.g. serial number, MAC address, socket ID network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/44 Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs
• CPC Class Codes: H04N 21/4622 : Retrieving content or additional data from different sources, e.g. from a broadcast channel and the Internet web site content organization and management for information retrieval from the Internet G06F16/958; transmission by internet of broadcast information H04H60/82; stock exchange data over packet-switching network H04L12/1804; push services including data channel over packet-switching network H04L12/1859
• CPC Class Codes: H04N 21/4627 : Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/63345 : by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 21/835 : Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 2201/323 : for tracing or tracking, e.g. forensic tracing of unauthorized copies
• CPC Class Codes: H04N 2201/3236 : Details of authentication information generation
• CPC Class Codes: H04N 7/163 : by receiver means only

Abstract

This invention provides a method for identifying a purchaser who purchased content from which an illegal copy was produced. A provider system encrypts a content purchased by the purchaser using a public key of a purchaser system and sends the encrypted content to the purchaser system. The purchaser system creates a digital signature of the content with the use of a private key of its own and embeds the created digital signature into the received content. When an illegal copy is found, the provider system verifies the digital signature, embedded in the illegal copy as a digital watermark, to identify the purchaser who purchased the content from which the illegal copy was produced.

Claims

1. An embed-in-content information processing method for embedding information on k (k is an integer equal to or larger than 2) content-handling persons using an electronic computer, the method comprising the steps of:

creating a digital signature of a first content-handling person by encrypting a hash value using a private key in accordance with a public key cipher system of the first content-handling person, the hash value being created by evaluating the content with a first hash function;

sequentially repeating digital signature creation for a second person to a k-th content-handling person to create the digital signatures of the content-handling persons; and

embedding the digital signature of the k-th content-handling person into the content such that the digital signature of the k-th content-handling person cannot be separated from the content without using a predetermined rule, the digital signature of the k-th content-handling person being obtained by performing said digital signature creation for the k-th content-handling person, wherein, during said digital signature creation processing for an i-th content-handling person (i is an integer between 2 and k), a value dependent on the digital signature of the (i-1)th content-handling person is encrypted using the private key of the i-th content-handling person to generate the digital signature of the (i-)th content-handling person.

2. An embed-in-content information processing method according to claim 1, wherein the value dependent on the digital signature of the (i-1)th content-handling person is a hash value obtained by evaluating the value of the digital signature of said (i-1)th content-handling person with a hash function.

3. In a system in which at least one client terminal, at least one Worldwide Web (WWW) server providing information upon request from said client terminal, and at least one mark management server managing one or more marks used by said client terminal, said client terminal, said WWW server and said mark management server are interconnected over a communication network, a Web page authentication method, for a Web page published on the WWW server, the method comprising:

sending, by said WWW server, a mark-send request containing information for specifying said WWW server to said mark management server;

pasting, by said WWW server, the mark sent back from said mark management server into the Web page of said WWW server;

setting in the Web page a link to said mark management server;

publishing, by said WWW server, the Web page containing the mark for access by said client terminal;

storing, by said mark management server, in a mark management database (DB), such information as to whether the mark managed by the mark management server has been sent;

checking, by said mark management server, upon receiving the mark-send request from said WWW server, if the WWW server satisfies a condition for acquiring the mark, and only when the condition is satisfied, updating said mark management DB, and then sending the requested mark back to the WWW server;

referencing, by said mark management server, upon receiving a validity check request from said client terminal, said mark management DB to verify if the requested mark is valid and sending a verification result back to the client terminal;

downloading, by said client terminal, the Web page containing said mark from said WWW server; and

sending, by said client terminal, the validity check request including information specifying said Web page containing said mark and receiving the verification result.

4. A method according to claim 3, wherein said information specifying said WWW server is a URL of said WWW server.

5. A method according to claim 3, wherein said link to said mark management server is set in said mark contained on said web page.

6. A method according to claim 3, wherein said link to said mark management server is set by said WWW server.

7. A method according to claim 3, wherein said mark management server comprises:

a mark issuance server which issues marks; and

a mark verification server which authenticates marks.

8. In a system in which at least one client terminal, at least one Worldwide Web (WWW) server providing information upon request from said client terminal, and at least one mark management server managing one or more marks used by said client terminal, said client terminal, said WWW server and said mark management server are interconnected over a communication network, a Web page authentication method, for a Web page published on the WWW server, the method comprising:

sending, by said WWW server, a mark-send request containing information specifying said WWW server to said mark management server;

pasting, by said WWW server, a signature-containing mark sent back from said mark management server into the Web page of the WWW server and publishing the Web page containing the signature-containing mark for access by said client terminal;

storing, by said mark management server, in a mark management database (DB), such information as to whether the mark managed by the mark management server has been sent;

receiving in said client terminal a public key of said mark management server from said mark management server;

checking, by said mark management server, upon receiving the mark-send request from said WWW server, if said WWW server satisfies a condition for acquiring the mark, and only when the condition is satisfied, updating said mark management DB, adding a digital signature to information specifying said WWW sever contained in said request to generate a signature-containing mark, and then sending the signature-containing mark back to the WWW server;

storing, by said client terminal, in a public key DB the public key sent back from said mark management server;

downloading, by said client terminal, from said WWW server a Web page in which said mark is pasted; and

referencing, by client terminal, said public key DB to verify the signature contained in the downloaded Web page in which said mark is pasted.

9. A Web page authentication method according to claim 8, wherein the signature-containing mark is generated not only for the information specifying said WWW server but also for image data of the mark to generate the signature-containing mark from the mark and the signature.

10. A Web page authentication method according to claim 8, wherein the signature-containing mark is generated for the Web page to generate the signature-containing mark from the mark and the signature.

11. A Web page authentication method according to claim 8, wherein not only the mark and the signature but also attribute information associated with the system is used as a component of the signature-containing mark.

12. A method according to claim 8, wherein said information specifying said WWW server is a URL of said WWW server.

13. A method according to claim 8, wherein said client terminal sends a public key send request to said mark management server and said mark management server sends a public key to said client terminal in response to said public key send request.

14. A method according to claim 8, wherein said client terminal receives a public key from said mark management server after said client terminal downloads said web page.

15. A method according to claim 8, wherein said information specifying said web server is one of a URL of said WWW server, said mark, and said web page.

16. A method according to claim 8, wherein said mark management server comprises:

a mark issuance server which issues marks; and

a mark verification server which authenticates marks.

17. A Web page authentication system comprising:

an information browser device for browsing a Web page;

an information publisher device for publishing a Web page; and

a mark manager device for managing a mark for authenticating the Web page published by said information publisher device,

wherein said information publisher device comprises;

publishing means for publishing a Web page in which link information to said mark manager device has been set,

wherein said information browser device comprises;

Web display means for displaying the Web page published by said information publisher device on a display device together with a mark for authenticating said Web page, said mark managed by said mark manager device, and

check requesting means for sending a check request to check validity of said Web page to said mark manager device determined by said link information set on said Web page in response to an operation by a user to select the mark displayed on said display device together with the Web page, and

wherein said mark manager device comprises;

check information sending means for sending, upon receipt of said check request, necessary information to check the validity of the Web page whose validity is to be checked to an originator of said check request.

18. A Web page authentication system according to claim 17, wherein said mark manager device further comprises;

verification means for checking the validity of said Web page whose validity is to be checked, upon receipt of said check request,

wherein said check information sending means in said mark manager device sends a check result by said verification means to said originator of said check request as said information necessary for checking the validity of the Web page whose validity is to be checked, and

wherein said information browser device further comprises;

validity check result display means for displaying the check result on the display device when the check result indicates that the Web page has been verified.

19. A Web page authentication system according to claim 18, wherein said information browser device constructs said check result display means on the information browser device itself in accordance with the information sent through a communication network.

20. A Web page authentication system according to claim 18, wherein said mark manager device further comprises:

storage means for storing information relative to the Web page authenticated by the mark managed by the mark management device itself, and

wherein said verification means in said mark manager device, upon receipt of said check request, executes validity check as to the Web page by checking the information stored in said storage means and concerning the Web page that is authenticated by the mark displayed together with said Web page on said display device of said information browser device.

21. A Web page authentication system according to claim 20, wherein said check request contains data for uniquely identifying the Web page to be checked and/or a publisher of the Web page,

wherein said storage means of said mark manager device stores data for uniquely identifying the Web page authenticated by the mark managed by the device itself and/or the publisher of the Web page as information concerning said Web page, and

wherein said verification means of said mark manager device, upon receipt of said check request, checks the validity of the Web page by comparing the data for uniquely identifying the Web page to be checked and/or the publisher of said Web page contained in said check request with the data stored in said storage means.

22. A Web page authentication system according to claim 21, wherein said data for uniquely identifying the Web page and/or the publisher of said Web page is URL data.

23. A Web page authentication system according to claim 21, wherein said data for uniquely identifying the Web page and/or the publisher of said Web page is a characteristic value of data constructing said Web page.

24. A Web page authentication system according to claim 17, wherein said mark manager device further comprises:

mark sending means for checking the sending request for authentication of the Web page, upon receipt of said sending request and for sending the mark to an originator of said sending request if said sending request satisfies a predetermined condition.

25. An information browser device for browsing a Web page, comprising:

Web display means for displaying a Web page on which link information leading to a mark manager device who manages a mark for authentication of the Web page has been set together with the mark for authentication of said Web page, said mark managed by said mark manager device; and

check requesting means for sending a check request to check the validity of the Web page to said mark manager device, which is determined by the link information set on said Web page in accordance with an operation of a user to select the mark displayed in said display device together with the Web page.

26. An information browser device according to claim 25, further comprising:

check result display means for displaying the result of checking the validity on the display device, upon receipt of said check result if said result indicates that the Web page has been verified.

27. An information browser device according to claim 26, wherein said check result display means is constructed in accordance with information sent through a communication network.

28. A mark manager device for managing a mark for authenticating a Web page, comprising:

means for receiving a check request to check the validity of said Web page said check request being generated by an operation of a user of a information browser device for browsing the Web page to select a mark displayed together with the Web page; and

check information sending means for sending information necessary for checking the validity of the Web page to an originator of the check request in response to said check request.

29. A mark manager device according to claim 28, further comprising:

verification means for checking the validity of the target Web page upon receipt of said check request,

wherein said check information sending means sends a check result obtained by said verification means to an originator of the check request as information necessary for checking the validity of the Web page.

30. A mark manager device according to claim 29, further comprising:

storage means for storing information as to the Web page which is authenticated by the mark managed by said mark manager device, and

wherein said verification means executes, upon receipt of said check request, checking of the validity of the Web page by checking the information stored in said storage means and concerning the Web page that is authenticated by the mark displayed together with the Web page in said information browser device.

31. A mark manager device according to claim 30, wherein said check request contains data for uniquely identifying the Web page and/or the publisher of said Web page,

wherein said storage means stores data for uniquely identifying the Web page that is authenticated by the mark managed by said device itself and/or the publisher of the Web as information concerning said Web page, and

wherein said verification means, upon receipt of said check request checks the validity of the Web page by comparing the data uniquely identifying the Web page and/or the publisher of the Web page contained in said check request with the data stored in said storage means.

32. A mark manager device according to claim 28, further comprising:

sending request receiving means for receiving a sending request of a mark for authentication of the Web page; and

mark sending means, upon receipt of said sending request, for checking said sending request and if said sending request satisfies a predetermined condition, for sending the mark to the originator of said sending request.

33. An information publisher device for publishing a Web page, comprising:

means for setting link information to a mark manager device managing a mark for authentication of the Web page on said Web page so that an information browser device for browsing the web page is capable of sending a check request to check the validity of the Web page to the mark manager device in accordance with an operation of a user of the information browser device to select the mark displayed together with the Web page.

34. A recording medium storing a program therein for constructing an information browser device for browsing a Web page on a computer, wherein said program is read and executed by the computer to construct, on the computer:

Web display means for displaying the Web page in which link information leading to a mark manager side managing a mark for authenticating the Web page has been set in a display device together with the mark managed by said mark manager for authenticating the Web page; and

check request means for sending a check request to check the validity of the Web page to said mark manager device which is determined by the link information set on said Web page in response to an operation by the user to select the mark displayed on said display device together with the Web page.

35. A recording medium storing a program therein for constructing a mark manager device for managing a mark for authenticating a Web page on a computer, wherein said program is read and executed by the computer to construct, on the computer:

means for receiving a check request to check the validity of the Web page said check request generated in accordance with an operation of a user of an information browser device for browsing the Web page to select the mark displayed together with the Web page; and

check information sending means for sending information necessary for checking the validity of the Web page to an originator of said check request in response to said check request.

36. A recording medium storing a program therein for constructing an information publisher device for publishing a Web page on a computer, wherein said program is read and executed by the computer to construct, on the computer:

means for setting link information to a mark manager device managing a mark for authentication of the Web page said Web page so that an information browser device for browsing the Web page is capable of sending a check request to check the validity of the Web page to the mark manager device in accordance with an operation of a user of the information browser device to select the mark displayed together with the Web page.

37. A Web page authentication system comprising:

an information browser device for browsing a Web page;

an information publisher device for publishing a Web page; and

a mark manager device for managing a mark for authenticating the Web page published by said information publisher device,

wherein said information publisher device comprises;

mark sending request means for sending a sending request of a mark in which information for checking the validity of the Web page is embedded as a digital watermark to said mark manager device, and

publishing means for publishing said mark sent from said mark manager device by pasting said mark on said Web page,

wherein said mark manager device comprises;

mark generating means for generating said mark in response to the sending request of the mark, and mark sending means for sending said mark generated by said mark generating means to an originator of said sending

request of the mark, and

wherein said information browser device comprises;

downloading means for downloading the Web page published by said information publisher device and on which said mark is pasted thereon,

validity check information extraction means for extracting information for checking the validity of the Web page embedded in the mark as a digital watermark, the mark being pasted on said Web page downloaded by said downloading means, and

extracted information display means for displaying on a display device the information for checking the validity of the Web page extracted by said validity check information extraction means.

38. A Web page authentication system according to claim 37, wherein said validity check information extraction means of said information browser device extracts the validity check information embedded in the mark pasted on said Web page as the digital watermark, in response to a request from a user to check the validity of the Web page downloaded by said downloading means.

39. A Web page authentication system according to claim 38, said mark manager device further comprises:

determining means for determining whether the sending request satisfies a predetermined condition, upon receipt of the sending request; and

wherein said mark generating means in the mark manager device generates said mark if said determining means determines that said sending request satisfies said predetermined condition.

40. A Web page authentication system according to claim 38, said information browser device further comprises:

Web display means for displaying the Web page downloaded by said downloading means; and

wherein said information browser device accepts the validity check request as to said Web page originated by an operation of the user to select the mark pasted on the Web page currently displayed.

41. A Web page authentication system according to claim 38, wherein said information publishing means in said information publishing device sets, on the Web page on which the mark sent from said mark manager device is pasted, link information to said mark manager to publish the Web page,

wherein said information publisher device further comprises:

check requesting means for sending a check request received from a user of the information publisher device to check the validity of the Web page downloaded by said downloading means to said mark manager device determined by the link information set on said Web page, and

wherein said mark manager device further comprises;

check information sending means for sending, upon receipt of said check request, necessary information for checking the validity of the Web page to an originator of said check request.

42. A Web page authentication system according to claim 41, wherein said mark manager device further comprises:

verification means for checking the validity of the Web page, upon receipt of said check request,

wherein said check information sending means in said mark manager device sends a check result by said verification means to the originator of said check request as necessary information for checking the validity of the Web page, and

wherein said information browser device further comprises;

check result displaying means for receiving said check result from said mark manager device and displaying said result on a display device.

43. A Web page authentication system according to claim 42, wherein said check result display means in said information publisher device displays the check result when said check result received from said mark manager device indicates that the Web page has been verified.

44. A Web page authentication system according to claim 37, wherein information for checking the validity of the Web page to be embedded in the mark as the digital watermark contains data which uniquely identifies said Web page and/or the publisher of said Web page.

45. A Web page authentication system according to claim 44, wherein said data which uniquely identifies said Web page and/or the publisher of said Web page is URL data.

46. A Web page authentication system according to claim 44, wherein said data which uniquely identifies said Web page and/or the publisher of said Web page is a characteristic value of the data constructing said Web page.

47. A Web page authentication system according to claim 37, wherein said mark generating means in said mark manager device generates a digital signature, using a private key of said mark manager device, as to the information for checking the validity of the Web page published by said information publisher device which had sent said sending request of the mark, and embeds said digital signature in the mark as a digital watermark, and

wherein said information publisher device further comprises:

means for verifying said digital signature embedded in the mark as the digital watermark, said mark sent from said mark manager device, using a public key which matches said private key of said mark manager device.

48. A Web authentication system according to claim 47, wherein said mark generating means in said mark manager device generates said digital signature by including a characteristic value of the mark in an object of the signature.

49. An information browser device for browsing a Web page, comprising:

downloading means for downloading a Web page on which a mark is pasted, and information for checking the validity of the Web page said mark being embedded in said mark as a digital watermark;

validity check information extracting means for extracting the information for checking the validity of the Web page which is embedded in the mark as the digital watermark from the mark pasted on the Web page downloaded by said downloading means; and

extracted information display means for displaying the validity check information extracted by said validity check information extracting means.

50. An information browser device according to claim 49, wherein said validity check extracting means extracts information for checking the validity of the Web page which is embedded in the mark as the digital watermark from the mark pasted on the Web page, in response to a validity check request from a user to check the validity of the Web page that was downloaded by said downloading means.

51. An information browser device according to claim 50, further comprising:

Web display means for displaying the Web page in a display device downloaded by said downloading means,

wherein said information browser device receives the Web page validity check request by an operation of the user to select the mark pasted on the Web page which is currently displayed on the display device.

52. An information browser device according to claim 50, wherein link information is set on said Web page having the mark pasted thereon, and

wherein said information browser device further comprises:

check requesting means for sending the Web page validity check request received from said user as to the Web page downloaded by said downloading means to an address determined by said link information that is set on said Web page.

53. A mark manager device for generating a mark to be pasted on a Web page published by an information publisher device, comprising:

mark generating means for generating the mark by embedding information for checking the validity of the Web page to be published by the information publisher device into the mark as a digital watermark in response to the sending request from said information publisher device; and

mark sending means for sending the mark generated by said mark generating means to an originator of said sending request.

54. A mark manager device according to claim 53, further comprising:

determining means for determining, upon receipt of the sending request, whether said sending request satisfies a predetermined condition,

wherein said mark generating means, upon determination that said sending request satisfies the predetermined condition, generating the mark.

55. A mark manager device according to claim 53, further comprising:

check information sending means for sending necessary information for checking the validity of the Web page to the originator of the validity check request, upon receipt of the validity check request as to the Web page published by said information publisher device and on which the mark is pasted.

56. A mark manager device according to claim 55, further comprising:

verification means for checking the validity of the Web page, upon receipt of said validity check request,

wherein said validity check information sending means sends a verification result by said verifying means to said originator of the check request as information necessary for checking the validity of the Web page.

57. A mark manager device according to claim 53, wherein said mark generating means generates a digital signature, using the private key of said mark manager device, as to information for checking the validity of the Web page published by said information publisher device which had sent the sending request, and embeds said digital signature into the mark as the digital watermark.

58. An information publisher device publishing a Web page, comprising:

mark sending request means for sending a sending request of the mark in which information for checking the validity of the Web page is embedded as a digital watermark to the mark manager device which generates the mark; and

publishing means for publishing said mark sent from said mark manager device by pasting said mark on said Web page.

59. An information publisher device according to claim 58, wherein said publishing means sets, on the Web page on which the mark sent from said mark manager device is pasted, link information to said mark manager to publish the Web page.

60. An information publishing device according to claim 58, wherein said mark sent from said mark manager device contains the digital signature generated using a private key of said mark manager device as to information for checking the validity of the Web page, said digital signature being embedded in said mark, and

wherein said information publishing device further comprising verifying means for verifying the digital signature embedded in the mark sent from said mark manager device as the digital watermark by using a public key which pairs with said private key of said mark manager device.

61. A recording medium storing a program therein for constructing an information browser device for browsing a Web page on a computer said program being read and executed by the computer to construct, on the computer:

downloading means for downloading the Web page on which a mark is pasted, and information for checking the validity of the Web page being embedded in said mark as a digital watermark;

validity check information extraction means for extracting the information embedded as the digital watermark in said mark pasted on said Web page downloaded by said downloading means; and

extracted information display means for displaying the information for checking the validity of the Web page extracted by said validity check information extracting means on a display device.

62. A recording medium storing a program therein for constructing a mark manager device for generating a mark to be pasted on a Web page published by an information publisher device on a computer, said program being read and executed by the computer to construct, on the computer:

mark generating means for generating a mark by embedding information for checking the validity of the Web page published by the information publisher device in the mark in a form of a digital watermark, in accordance with a sending request sent from said information publisher device; and

mark sending means for sending said mark generated by said mark generating means to an originator of said sending request.

63. Recording medium storing a program therein for constructing an information publishing device for publishing a Web page on a computer, said program being read and executed by the computer to construct, on the computer:

mark sending request means for sending a sending request of a mark in which information for checking the validity of the Web page is embedded as a digital watermark to the mark manager device which generates the mark; and

publishing means for publishing the mark sent from said mark manager device by pasting said mark on the Web page.