Protection of the distribution of digital documents in a peer to peer network

• US 20050044146A1
• Filed: 06/02/2004
• Published: 02/24/2005
• Est. Priority Date: 06/02/2003
• Status: Active Grant

• Current Assignee: LOT Network Inc.
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Viger, Pascal, Nassor, Eric, Maze, Frederic
• Granted Patent: US 7,966,491 B2
• Time in Patent Office: Days
• US Class Current: 709/205
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/1063 Discovery through centralising entities
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

This method of distributing a document comprises: a step of receiving a request for obtaining the document; a step of controlling the access rights to the document; the distribution of the document if it is available locally and access thereto is authorized; and the sending of the address of a second system likely to contain this document in the contrary case.

Claims

1. A central server in a network of the hybrid peer to peer type comprising:

means for receiving a request from a client for obtaining a digital document by that client, said request containing a reference of said document;

means for selecting a peer system of the network likely to contain said document;

means for generating an access key for controlling access to the document by said client, said means for generating the access key being adapted to generate said access key by an encrypting method using a private key of said central server, the time and the address of said client on the network; and

means for sending a message to the client, comprising the reference, the address of the peer system on the network and the access key.

2. A central server according to claim 1, further comprising means for authenticating an identifier of a user of said client, and

wherein said encrypting method also uses said identifier.

3. A central server according to claim 1, wherein the sending means are adapted to send said message in the form of a page containing:

a first window managed by said central server, said first window comprising a link whose activation generates the sending of a request to said central server in order to obtain the address of a second peer system likely to contain said digital document; and

at least one second window intended to be managed by said peer system or said second peer system.

4. A central server according to claim 1, wherein the sending means are adapted to send said message in the form of an HTTP response of the forward type.

5. A method of protecting the distribution of a digital document, this protection method being able to be implemented in a central server of a network of the hybrid peer to peer type and comprising:

a step of receiving a request from a client for obtaining a document by that client, said request comprising a reference of said document;

a step of selecting a peer system of said network likely to contain said document;

a step of generating an access key for controlling access to the document by the client, said step of generating the access key, comprising a generation of said key by an encrypting method using a private key of said central server, the time and the address of said client on the network;

a step of sending a message to said client, comprising said reference, the address of said peer system on said network and said access key.

6. A protection method according to claim 5, further comprising a step of authenticating an identifier of a user of said client;

and

wherein said encrypting method also uses said identifier of the user of the client.

7. A protection method according to claim 5, wherein, during said sending step, said message is sent in the form of a page containing:

a first window managed by said central server, said first window comprising a link whose activation generates the sending of a request to said central server in order to obtain the address of a second peer system likely to contain said digital document; and

at least one second window intended to be managed by said peer system or said second peer system.

8. A protection method according to claim 5, wherein, during said sending step, said message is sent in the form of an HTTP response of the forward type.

9. A system in a network comprising:

means for receiving a request from a client for obtaining a digital document for that client;

means for obtaining an address of at least one second system likely to contain said document;

means for comparing at least one attribute of said system with at least one corresponding attribute of said at least one second system; and

means for sending said address of said at least one second system to said client according to a result supplied by said comparison means.

10. A system according to claim 9, further comprising access control means adapted, using an access key included in said request for controlling access to the document by said client, to validate or refuse the request.

11. A system according to claim 9, further comprising means for distributing to said client at least part of said document in a memory accessible to said system.

12. A system according to claim 10, wherein the access control means comprise decrypting means using a public key of a central server in said network, said decrypting means being adapted to obtain a time from the access key;

and

said access control means are adapted to

a) validate the request when the time elapsed since said time is less than a predetermined time; and

b) refuse the request otherwise.

13. A system according to claim 12, wherein

said means of receiving a request are adapted to obtain the address of said client from the request;

said decrypting means are adapted to obtain a second address using the access key; and

said access control means are adapted to

a) validate the request when said second address is identical to said address of said client; and

b) refuse the request otherwise.

14. A system according to claim 12, wherein

said decrypting means are adapted to obtain an identifier of a user of the client using the access key;

and

said access control means are adapted to validate and refuse the request after having verified the rights of access to said document by said user from said identifier.

15. A system according to claim 9, wherein said means for obtaining the address of at least one second system are adapted to send an invitation message containing the reference of said document to at least one second system and to receive a confirmation message from at least one second system when said document is available in a memory accessible to said system.

16. A system according to claim 15, wherein said confirmation message signifies the fact that said user is authorized to access said document from said at least one second system originating said confirmation message.

17. A system according to claim 16, wherein said means for obtaining the address of at least one second system are adapted to send said identifier of the user in said invitation message.

18. A system according to claim 9, wherein said at least one attribute of the system and said at least one attribute of the second system represent the load or the communication capacities of said systems, the number of digital documents stored or the number of documents or document parts distributed by said systems.

19. A system according to claim 14, wherein said at least one attribute of the system and said at least one attribute of the second system represent the number of documents available for said user on these systems.

20. A method of distributing a digital document able to be used in a system of a network, comprising

a step of receiving a request, from a client, for obtaining said document for said client;

a step of obtaining the address of at least one second system likely to contain said document;

a step of comparing at least one attribute of said system with at least one corresponding attribute of said at least one second system; and

a step of sending said address of said at least one second system to said client according to a result of said comparison step.

21. A distribution method according to claim 20, further comprising an access control step adapted, using an access key included in said request for controlling access to the document by said client, to validate or refuse the request.

22. A distribution method according to claim 20, further comprising a step of distributing to said client at least part of said document in a memory accessible to said system.

23. A distribution method according to claim 21, wherein there are performed, during said access control step,

a decrypting substep using a public key of a central server of said network, said decrypting substep being adapted to obtain a time from the access key;

and in that

during said access control step;

a) access to the document by said client is authorized when the time elapsed since said time is less than a predetermined time; and

b) said access is refused otherwise.

24. A distribution method according to claim 23, wherein

during said step of receiving a request, the address of said client is obtained from the request;

in that there is obtained, during said decrypting substep, a second address from the access key; and

during said access control step;

a) access to the document is authorized when said second address is identical to said address of the client; and

b) said access is refused otherwise.

25. A distribution method according to claim 23, wherein

during said decrypting substep an identifier of a user of the client is obtained using the access key;

and also comprising;

an authentication step during which the rights of access to the document by said user are verified from said identifier; and

in that;

during said access control step, the request is validated or refused according to said access rights.

26. A distribution method according to claim 20, wherein, during said step of obtaining the address of at least one second system:

an invitation message containing the reference of said document is sent to said at least one second system; and

a confirmation message is received coming from at least one second system when said document is available in a memory accessible to said system.

27. A distribution method according to claim 25, wherein said identifier of the user is sent in an invitation message.

28. A distribution method according to claim 27, wherein a confirmation message is received coming from said at least one second system if said user is authorized to access said document from said system.

29. A distribution method according to claim 20, wherein said at least one attribute of the system and said at least one attribute of the second system represent the load or the communication capacities of said systems, the number of digital documents stored or the number of documents or document parts distributed by said systems.

30. An information medium which can be read by a computer system, possibly totally or partially removable, in particular a CD-ROM or magnetic medium such as a hard disk or a diskette, or a transmittable medium such as an electrical or optical signal, wherein said information medium contains instructions of a computer program for implementing a protection method according to any one of claims 5 to 8 and/or a distribution method according to any one of claims 20 to 29 when this program is loaded in and executed by a computer system.

31. A computer program stored on an information medium, said program containing instructions for implementing a protection method according to any one of claims 5 to 8, and/or a distribution method according to any one of claims 20 to 29, when this program is loaded in and executed by a computer system.