Method and system for proving ownership of digital data

• US 6,856,977 B1
• Filed: 09/21/2000
• Issued: 02/15/2005
• Est. Priority Date: 09/21/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Pfitzmann, Birgit, Sadeghi, Ahmad-Reza, Adelsbach, André
• Primary Examiner(s): Elisca, Pierre E.
• Application Number:
  US09/666,256
• Time in Patent Office: 1,608 Days
• Field of Search: 705/57, 705/50, 705/51, 705/58, 705/156, 713200-202, 713/168, 713/176, 713/229, 380/200, 380/201, 380/203, 380/204, 380/277, 380/278, 380/284
• US Class Current: 705/57
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions

Abstract

A system for proving ownership of digital media works. Proof of ownership of such type of work is provided by a protocol for registering a work with a registration center thus providing the rightful owner or copyright holder of the work with an ownership certificate. There is also provided a protocol for proving to another party who is a prospective buyer or licensee, that an ownership claim is correct and valid by providing the ownership certificate when required. Another protocol is utilized for showing to a third party, a prospective buyer or licensee, that a second party has correctly obtained the corresponding work from the rightful copyright owner.

Claims

1. A method for proving ownership of a digital work W, involving a copyright owner H of said work, a registration center RC, and at least one third party D, comprising the following protocols:

automatically plementing an ownership registration protocol for identifying said owner H, and his/her work W to be registered to said registration center RC;

wherein said ownership registration protocol is a two-party protocol between the owner H and said registration center RC concerning his/her original work W_i to be registered,

in said ownership registration protocol, said owner H then obtaining a proof of ownership certificate, by way of a proof string proof_H identifying said owner H and said work W and, potentially, any other work W″

derived from said work W; and

said registration center RC performing a similarity test to prevent multiple registrations of similar works and

transmitting a certificate to owner H of a form;

proof_H=sign_RC(Id_H, h(W), h(W′

), testinf_W, reg_time, reg_text), wherein Id_W, identifies owner H, h(W), h(W′

) denote hash values of a collision free hash function h, reg_time denotes a registration time, and reg_text denotes a textual description of the registration;

implementing a proof of ownership protocol which enables said owner H to prove his/her ownership in said work W, and in any other work derived from said work, W to said third party D, and

implementing a show protocol which enables said third party D to demonstrate his/her legitimate rights in said work W, that he/she has obtained a proof of ownership from a rightful owner of the work W.

2. The method according to claim 1 further comprising implementing an initialization protocol for setting up the system, comprising using cryptographic key generation for the parties involved.

3. The method according to claim 2 wherein said initialization protocol utilizes a cryptographic key exchange by which each party involved obtains a key pair and an authentic public key of each other party.

4. The method according to claim 1 wherein the method of implementing said ownership registration includes:

modifying the original work W resulting in a modified work W′

, in particular by introducing imperceptible modifications like watermarks or fingerprints,

transferring said modified work W″

to the owner H for distribution.

5. The method according to claim 4 wherein said registration protocol has the form

HRC$\underset{\to <br><br>}{{\mathrm{sign}}_H\; <li></li>\left(W\right)<br><br>\text{\hspace{1em}<br><br>}}$IF registered?(W) THEN failed! ELSE sim_init(W,*);

proof_H O.K.$\underset{\leftarrow <br><br>}{\text{\hspace{1em}<br><br>}<br><br>\left(W^{*},{\mathrm{proof}}_H\right)}<br><br>\text{\hspace{1em}<br><br>}.$

6. The method according to claim 4 wherein said registration protocol is extended and has the form

HRC$\underset{\to <br><br>}{\mathrm{com}\; <li></li>\text{\hspace{1em}<br><br>}}$$\underset{\leftarrow <br><br>}{\text{\hspace{1em}<br><br>}<br><br>\mathrm{receipt}}$$\underset{\to <br><br>}{\mathrm{open}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{com}<br><br>\text{\hspace{1em}<br><br>}}$IF registered?(W) THEN$\underset{\leftarrow <br><br>}{\text{\hspace{1em}<br><br>}<br><br>\mathrm{refuse}<br><br>\text{-}<br><br>{\mathrm{proof}}_W}$ELSE sim_init(W,*);

proof_H O.K.?$\underset{\leftarrow <br><br>}{\text{\hspace{1em}<br><br>}<br><br>\left(W^{\mathrm{\prime <br><br>}},{\mathrm{proof}}_H\right)}$$\underset{\to <br><br>}{{\mathrm{sign}}_H<br><br>\left(W\right)<br><br>\text{\hspace{1em}<br><br>}}$If registered?(W) THEN failed! ELSE sim_init(W,*);

proof_H O.K.?$\underset{\leftarrow <br><br>}{\text{\hspace{1em}<br><br>}<br><br>\left(W^{*},{\mathrm{proof}}_H\right)}<br><br>\text{\hspace{1em}<br><br>}.$

7. The method according to claim 1, wherein said proof of ownership protocol is a two party protocol between owner H and third party D, and the registration center RC, wherein

said owner H transmitting a possibly modified version of the work W, denoted W″

with the proof string or certificate proof_H and a signed statement to said third party D,

said third party D performing a local similarity test sim_test(W″

, testingf_W) whose putput to D is a proof string proof_D particularly consisting of init_proof_D.

8. The method according to claim 1, wherein said proof of ownership protocol is a three-party protocol among said owner H, said third party D, and said registration center RC, wherein

said owner H transmitting a possibly modified work W″

for which he/she wants to prove his/her ownership with the certificate proof_H and a signed statement to said third party D,

said third party D requesting the confirmation of said registration center RC on the validity of claimed ownership and

said registration center RC testing in a subprotocol whether the first registered work, to which W″

is similar, was registered by H.

9. The method according to claim 8 wherein said proof of ownership protocol used in said method has the form

HDRC$\underset{\to <br><br>}{\left(W^{\mathrm{″\; <li></li>}}\right),{\mathrm{init\_proof}}_D<br><br>\text{\hspace{1em}<br><br>}}$init_proof_DO.K.? proof_H O.K.? IF h(W″

) in proof_H? THEN output (true, init_proof_D)ELSE$\underset{\leftrightarrow <br><br>}{\text{\hspace{1em}<br><br>}<br><br>\mathrm{test})<br><br>{\mathrm{init\_proof}}_D<br><br>\text{\hspace{1em}<br><br>}}<br><br>\text{\hspace{1em}<br><br>}.$

10. The method according to claim 1, wherein

said show protocol used in said method is a two-party protocol between on third party D having successfully executed the proof of ownership process for a work W″

and another third party D′

to which said one party D intends to demonstrate its rights in work W″

.

11. The method according to claim 10, wherein said show protocol used in said method includes

said other third party D′

sending the test result proof_D and a modified work W′

to the other third party D′

,

said other third party D′

checking the components of proof_D, and

said other third party D′

accepting the demonstration is said check is positive.

12. The method according to claim 1 wherein said proof of ownership protocol used in said method has the form

DD′

13. A computerized system for proving copyright ownership of a digital work W, of an owner H, including a registration center RC, implemented by a group of protocols, said system comprising:

means for executing an initializing protocol for setting up said system, including cryptographic key generation for parties involved;

means for executing a registration protocol for identifying said owner H, and his/her work W to be registered to said registration center RC;

means for executing a proof of ownership protocol which enables said owner H to prove his/her ownership in said work W, and in any other work derived from said work, W to a third party D,

means for executing a show protocol which enables said third party D to demonstrate that he/she has legitimate rights in said work W wherein;

said means for executing said registration protocol further;

controls said registration center RC to perform a similarity test to prevent multiple registrations of similar works and

transmit to owner H a certificate of a form;

proof_H=sign_RC(Id_H, h(W), h(W′

), testinf_W, reg_time, reg_text), wherein Id_H identifies owner H, h(W), h(W′

) denote hash values of a collision free hash function h, reg_time denotes a registration time, and reg_text denotes a textual description of the registration.

14. The computerized system of claim 13, wherein said means for executing the initializing protocol generates cryptographic keys for the parties involved and provides a cryptographic key exchange by which each party obtains a key pair, including the authentic public key of each other party.

15. The computerized system of claim 13, wherein said means for executing the registration protocol comprises

means for producing a proof of ownership certificate for the owner H, including a proof string proof_H identifying said owner and said work W and, any other work W″

derived from said work W,

means for modifying said original work W resulting in a modified work W′

by introducing imperceptible modifications, and

means for transferring said modified work W′

to owner H for distribution.

16. The computerized system of claim 13, wherein said means for executing a proof of ownership protocol performs

either a two-party protocol between said owner H and said third party D, whereby said owner H transmits a modified version W″

of the work W with a proof string or certificate proof_H and a signed statement to said third party D, and said third party D performs a similarity test sim_test(W″

, testinf_W) whose output to D is a proof sting proof_D consisting of init_proof_H, or

a three-party protocol between among He said owner H, said third party D, and said registration center RC, whereby

said owner H transmits said modified work W″

with the certificate proof_H and a signed statement to said third party D, the latter requests a confirmation from said registration center RC on the validity of the claimed ownership and

said registration center RC tests in a subprotocol whether the first registered work, to which W″

is similar, was registered by H.

17. The computerized system of claim 13 wherein the means for executing said show protocol has

means for allowing a first party D to send said test result proof_Dand a modified work W″

to a second party D′

,

means for allowing said second party D′

to check the components of proof_D and to accept said first party'"'"'s claim of rights in work W′

is legitimate.