WO2006062358A1 - Method of revoking public key of content privider - Google Patents
Method of revoking public key of content privider Download PDFInfo
- Publication number
- WO2006062358A1 WO2006062358A1 PCT/KR2005/004191 KR2005004191W WO2006062358A1 WO 2006062358 A1 WO2006062358 A1 WO 2006062358A1 KR 2005004191 W KR2005004191 W KR 2005004191W WO 2006062358 A1 WO2006062358 A1 WO 2006062358A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- content
- content provider
- public key
- user device
- signature value
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 101
- 238000012795 verification Methods 0.000 claims description 38
- 238000004590 computer program Methods 0.000 claims description 5
- 239000013256 coordination polymer Substances 0.000 description 197
- 238000010586 diagram Methods 0.000 description 8
- 239000000284 extract Substances 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/32—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols 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
- H04L9/3263—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols 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 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements
- H04L9/3268—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols 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 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0891—Revocation or update of secret information, e.g. encryption key update or rekeying
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L2209/00—Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
- H04L2209/60—Digital content management, e.g. content distribution
Definitions
- the present invention relates to a method of revoking content authority using a revocation list, and more particularly, to a method of revoking a public key of a content provider in a system in which a certifying authority certifies the public key of the content provider and the content provider transmits content to a user using the certified public key.
- Content is provided from a content manufacturer to a content provider, and the content provider transmits the content to a user device.
- the content manufacturer is a studio
- the content provider is an Internet business firm or a disc manufacturing company that changes the content into mass media files and distributes them to a user device.
- the user device is designed to determine whether the content provider is an authorized content provider and to reproduce the content after the content provider is determined to be an authorized content provider. This is because a content right may be terminated at the expiration of a contract or a content provider may try to disguise himself or herself as another content provider.
- a method of determining whether a content provider is an authorized content provider includes user authentication that determines whether the content provider is a revoked content provider and whether the content provider disguises himself or herself as another content provider.
- the former is performed using a revocation list and the latter is performed using an electronic signature.
- FIG. 1 is a flowchart of a conventional method of revoking content authority.
- FIG. 2 is a diagram illustrating a structure of a revocation list used in the method of FIG. 1.
- a certificate authority CA makes a certificate C_CA_CP that certifies a CP public key PK_CP of a content provider CP and transmits a certificate to the CP (operation 110).
- the certificate C_CA_CP includes a signature value Sl generated by electronically signing the public key PK_CP using a private key SK_CA, and the public key PK_CP.
- the certificate C_CA_CP may be expressed as follows:
- the content provider generates content Cont and a certificate C_CP_UD that certifies the content Cont and transmits them to a user device UD (operation 120).
- the CP certificate C_CP_UD includes the certificate C_CA_CP, and a signature value S2 generated by electronically signing the content Cont using a private key SK_CP of the content provider.
- the certificate C_CP_UD may be expressed as follows:
- the user device UD extracts the signature values Sl and S2 and the public key PK_CP from the certificate C_CP_UD (operation 130).
- the user device UD determines whether the certificate C_CP_UD is revoked by checking whether a revocation list RL includes the public key PK_CP extracted in operation 130 (operation 140).
- the revocation list may include a public key PK_CP of a revoked content provider.
- the method proceeds to operation 150, and otherwise, the method proceeds to operation 170.
- the user device UD determines whether verification of the content
- the verification function V() is expressed as follows:
- the user device UD determines whether verification of the public key
- the verification function V() is expressed as follows:
- the user device UD determines the content provider CP as a revoked content provider when the public key PK_CP extracted in operation 130 is included in the revocation list, or as a content provider who disguises himself or herself as another content provider when verification is determined to fail in operation 150 or 160. In these cases, the user device UD rejects reproduction of the content Cont.
- the certificate authority CA transmits its certificate C_CA_CP to the content provider CP
- the content provider CP transmits the first content Cont_l to the user device UD using the certificate C_CP_UD of the content provider CP
- a revocation list RL stored in the user device UD is updated to include the certificate C_CP_UD at a time tl
- the content provider CP transmits second content Cont_2 to the user device UD using the revoked certificate C_CP_UD.
- the user device UD performs user authentication, which is described with reference to FIG. 1, for both the first and second contents Cont_l and Cont_2 using the revoked certificate C_CP_UD, and thus cannot reproduce both the first content Cont_l, and the second content Cont_2 transmitted after the time tl.
- the content provider CP is revoked for only a business reason, it is unreasonable to prevent the user device UD from using the first content Cont_l transmitted to the user device UD from the content provider CP before the time tl when the content provider CP was revoked. Disclosure of Invention
- the present invention provides a method of authenticating a content provider, which allows reproduction of content transmitted from the content provider before the content provider is revoked and a certificate of the revoked content provider cannot be updated, and revoking the content provider using the same.
- the present invention it is possible to allow a user device to identify content that must not be revoked by transmitting to the user device a revocation list which includes a time when content authority is revoked, and an exception list. Accordingly, it is possible to prevent rightly obtained content from being revoked.
- FIG. 1 is a flowchart of a conventional method of revoking content authority
- FIG. 2 is a diagram illustrating a structure of a revocation list used in the method of
- FIG. 1 A first figure.
- FIG. 3 is a flowchart of a method of revoking content authority according to an embodiment of the present invention.
- FIG. 4 is a diagram illustrating a structure of a revocation list used in the method of
- FIG. 3
- FIG. 5 is a flowchart of a method of revoking content authority according to another embodiment of the present invention.
- FIG. 6 is a diagram illustrating a structure of a revocation list used in the method of
- FIG. 5 A first figure.
- FIG. 7 is a flowchart of a method of revoking content authority according to yet another embodiment of the present invention.
- FIG. 8 is a diagram illustrating a structure of a revocation list used in the method of
- the method includes the user device determining whether the predetermined content is revoked by comparing a time when a signature of the public key is generated with a time when the public key is revoked. Accordingly, it is possible to allow the user device to identify content that must not be revoked according to the time when the public key is revoked and a revocation list which includes an exception list, thereby preventing rightly obtained content from being revoked.
- the present invention introduces two methods of preventing improper revocation of content authority.
- a revocation list is made to include information regarding a time when the content authority is revoked.
- the revocation list includes a content identifier for identifying the content of which content authority must not be revoked.
- a signature value of a certificate authority that the first method requires is different from that of the certificate authority that the second method requires.
- a certificate authority inserts information regarding a time when a signature of the certificate authority is made into a certificate to be provided to a content provider.
- a revocation list which is to be transmitted to a user device includes both a public key of a content provider to be revoked and information regarding a time when the public key is revoked.
- the user device determines whether each content authority must be revoked, according to the time when the signature is made and the time when the public key is revoked.
- a certificate authority inserts a content identifier to be signed into a certificate of the certificate authority to be provided to a content provider.
- a revocation list which is to be transmitted to a user device, includes both a public key of a content provider to be revoked, and an exception list specifying an identifier of content that must not be revoked.
- the user device determines whether each content authority must be revoked, using the content identifier and the exception list.
- FIGS. 3 and 5 illustrate embodiments of the first method according to the present invention
- FIG. 7 illustrates an embodiment of the second method according to the present invention.
- FIG. 3 is a flowchart of a method of revoking content authority Cont according to one embodiment of the present invention.
- FIG. 4 is a diagram illustrating a structure of a revocation list RL used in the method of FIG. 3.
- a certificate authority CA makes a certificate C_CA_CP certifying a public key of a content provider CP and transmits it to the content provider CP (operation 310).
- the certificate C_CA_CP includes the time Ts, the public key PK_CP, and a signature value Sl generated by electronically signing a public key PK_CP of the content provider CP and a time Ts using a private key SK_CA of the certificate authority CA.
- the time Ts denotes a time when the signature value S 1 is obtained.
- the method of FIG. 3 is different from that of FIG. 1 in that the signature value S 1 is obtained by electronically signing both the public key PK_CP of the content provider CP and the time Ts.
- the certificate C_CA_CP is expressed as follows:
- the content provider CP makes the content Cont and a certificate C_CP_UD certifying the content Cont and transmits them to a user device UD (operation 320).
- the certificate C_CP_UD includes the certificate C_CA_CP of the certificate authority CA, and a signature value S2 generated when the content Cont is electronically signed using a private key SK_CP of the content provider CP.
- [48] S(SK_CA, TsllPK_CP)IITsllPK_CPIIS(SK_CP, Cont) ... (6)
- the user device UD extracts the signature values Sl and S2, the time Ts, and the public key PK_CP of the content provider CP from the certificate C_CP_UD
- the user device UD checks whether the revocation list RL includes the public key PK_CP extracted in operation 130 (operation 340). If the public key PK_CP is not included, the method proceeds to operation 360, and otherwise, the method proceeds to operation 350. [51] Referring to FIG. 4, the revocation list RL used in the method of FIG. 3 lists the public key PK_CP of a revoked content provider and a time Tr when the public key
- PK_CP is revoked.
- the revocation list RL is safely transmitted from the certificate authority CA or a third authority to the user device UD.
- the user device UD determines whether the time Ts extracted in operation 330 is earlier than the time Tr listed in the revocation list RL (operation 350). If the time Ts is earlier than the time Tr, the method proceeds to operations 360 and 370, and otherwise, the method proceeds to operation 380. [53] In operations 360 and 370, whether the public key PK_CP is valid and whether the time Ts has been modified are determined.
- the user device UD determines whether verification of the content Cont succeeds or fails by inputting the signature value S2 and the public key PK_CP of the content provider CP and the content Cont into a verification function V() (operation 360). That is, whether the content Cont is signed using the private key SK_CP is verified.
- the verification function V() is expressed as follows:
- the user device UD determines whether the public key PK_CP is valid and whether the time Ts is modified by inputting the signature value Sl, the public key
- the signature value Sl is obtained by electronically signing both the public key PK_CP and the time Ts.
- the user device UD does not authenticate the content provider CP as an authorized content provider, and rejects reproduction of the content Cont (operation 380). That is, the user device UD determines the content provider CP as a revoked content provider when it is determined in operation 340 that the public key PK_CP is included in the revocation list RL and it is determined in operation 350 that the time Ts is later than the time Tr; determines that the content provider CP disguises himself or herself as another content provider when it is determined in operation 360 that verification fails; and determines that the time Tr is altered when it is determined in operation 370 that verification fails. In these cases, the user device UD rejects production of the content Cont.
- the user device UD can distinguish between a time Ts_A when a signature is generated when content Cont_A is transmitted from a content provider CPl, and a time Ts_B when a signature is generated when content Cont_B is transmitted from the content provider CPl. Accordingly, the user device UD can selectively determine whether each content authority is revoked.
- the time Ts is included in the signature value Sl of the certificate authority CA in operation 310, and verified when the signature value Sl is verified in operation 370. If the user device UD arbitrarily changes the time Ts transmitted in operation 310, verification in operation 370 will fail. Therefore, the user device UD should be prevented from changing the time Ts, and the security of content in the method of FIG. 3 should be protected.
- verification of the public key PK_CP may be omitted.
- the user device UD can manipulate the time Ts.
- operation 340 to determine whether the public key PK_CP is revoked may be performed after verifying the public key PK_CP (operations 360 and 370). That is, according to the present invention, the order of performing operations 340, 350, and 370 can be changed.
- the method of FIG. 3 is a two-step process in which the certificate authority CA authenticates the content provider CP.
- an upper certificate authority may further authenticate the certificate authority CA.
- the present invention further includes an operation in which the upper certificate authority issues a certificate certifying the certificate authority CA using an electronic signature, and an operation in which the user device UD verifies a signature value of the upper certificate authority.
- FIG. 5 is a flowchart of a method of revoking content authority Cont according to another embodiment of the present invention.
- FIG. 6 is a diagram illustrating a structure of a revocation list RL used in the method of FIG. 5.
- a certificate authority CA generates a certificate C_CA_CP certifying a public key PK_CP of a content provider CP and transmits it to the content provider CP (operation 510).
- the certificate C_CA_CP includes a signature value Sl which is obtained by electronically signing a content identifier ID-Cont, a time Ts when the signature S 1 is generated, and the public key PK_CP using a private key SK_CA of the certificate authority CA; the content identifier ID_Cont, the time Ts, and the public key PK_CP.
- the method of FIG. 5 is different from that of FIG. 1 in that the signature value S 1 is obtained by electronically signing the public key PK_CP of the content provider CP, the content identifier ID_Cont, and the time Ts.
- the certificate C_CA_CP is expressed as follows:
- [68] S(SK_CA, ID_ContllTsllPK_CP)IIID_ContllTsllPK_CP ... (9)
- the content provider CP makes content Cont and a certificate C_CP_UD certifying the content Cont and transmits them to a user device UD (operation 520).
- the certificate C_CP_UD includes the certificate C_CA_CP, and a signature value S2 obtained by electronically signing the content Cont using the private key SK_CP of the content provider CP.
- the certificate C_CP_UD is expressed as follows:
- the user device UD extracts the signature value Sl, the content identifier
- the user device UD determines whether the revocation list RL includes the public key PK_CP extracted in operation 530 (operation 540). If the public key PK_CP is not included, the method proceeds to operation 560, otherwise, the method proceeds to operation 550.
- the revocation list RL used in the method of FIG. 5 includes the public key PK_CP of the revoked content provider CP, a time Tr when the public key PK_CP is revoked, and a content revocation list RL_C_Rev.
- the user device UD determines whether the time Ts extracted in operation
- the user device UD determines whether the content revocation list
- RL C Rev of the revocation list RL includes the content identifier ID Cont extracted in operation 530 (operation 555).
- the method proceeds to operation 580, and otherwise, the method proceeds to operation
- the user device UD determines whether the public key PK_CP of the content provider CP is valid and whether the content identifier ID_Cont or the time Ts has been altered by inputting the signature value Sl, and the public key PK_CA of the certificate authority CA, the content identifier ID_Cont extracted in operation 530, the time Ts, and the public key PK_CP of the content provider CP into the verification function V() (operation 570).
- the verification function V() is given by Equation (12).
- the signature value Sl is obtained by electronically signing the public key PK_CP of the content provider CP, the content identifier ID_Cont, and the time Ts.
- V(Sl, PK_CA, ID_ContllTsllPK_CP) V(S(SK_CA, ID_ContllTsllPK_CP),
- ID_ContllTsllPK_CP Success or Fail ... (12)
- the user device UD does not authenticate the content provider CP as an authorized content provider and rejects reproduction of the content Cont. More specifically, the user device UD determines that the content provider CP is a revoked content provider when it is determined in operation 540 that the public key PK_CP is included in the revocation list RL and it is determined in operation 550 that the time Ts is later than the time Tr, determines that the content provider CP disguises himself or herself as another content provider when the verification in operations 560 and 570 fails, and determines that the content identifier ID_Cont or the time Ts has been altered when the verification in operation 570 fails. In these cases, the user device UD rejects reproduction of the content Cont. [86] In the method of FIG. 5, a content identifier to be revoked is included in a revocation list, thereby allowing precise selection of an object to be revoked.
- a user device is capable of selectively determining whether each content authority is to be revoked, based on a comparison between a time when a signature is generated and a time when a public key of a content provider is revoked.
- the content identifier ID_Cont and the time Ts are included in the signature value Sl of the certificate authority CA in operation 510, and the content identifier ID_Cont and the time Ts are verified when the signature value S 1 is verified in operation 570. Accordingly, the user device UD cannot manipulate the content identifier ID_Cont and the time Ts, thereby increasing the security for the method of FIG. 5.
- FIG. 7 is a flowchart of a method of revoking content authority Cont according to yet another embodiment of the present invention.
- FIG. 8 is a diagram illustrating a structure of a revocation list RL used in the method of FIG. 7.
- a certificate authority CA makes a certificate C_CA_CP certifying a public key PK_CP of a content provider CP and transmits it to the content provider CP (operation 710).
- the certificate C_CA_CP includes a signature value Sl obtained by electronically signing the public key PK_CP and a content identifier ID_Cont of the content provider CP using a private key SK_CA of the certificate authority CA; the content identifier ID_Cont; and the public key PK_CP of the content provider CP.
- the method of FIG. 7 is different from that of FIG. 1 in that the signature value S 1 is obtained by electronically signing the public key PK_CP and the content identifier ID_Cont.
- the certificate C_CA_CP is expressed as follows:
- the content provider CP makes a content Cont and a certificate C_CP_UD certifying the content Cont and transmits them to the user device UD (operation 720).
- the certificate C_CP_UD includes the certificate C_CA_CP, and a signature value S2 generated by electronically signing the content Cont using a private key SK_CP of the content provider CP.
- the certificate C_CP_UD is expressed as follows:
- [96] S(SK_CA, ID_ContllPK_CP)IIID_ContllPK_CPIIS(SK_CP, Cont) ... (14)
- the user device UD extracts the signature value Sl, the content identifier
- the user device UD determines whether the revocation list RL includes the public key PK_CP of the content provider CP extracted in operation 730 (operation 740). When the public key PK_CP is not included, the method proceeds to operation 760, and otherwise, the method proceeds to operation 750.
- the revocation list RL used in the method of FIG. 7 includes the public key PK_CP of a revoked content provider and an exception list RL_C_nonRev.
- the exception list RL_C_nonRev lists a content identifier of content that is not revoked although the public key PK_CP of the content provider CP who provides the content is included in the revocation list RL.
- the user device UD determines whether the content identifier ID_Cont extracted in operation 730 is included in the exception list RL_C_nonRev of the revocation list RL (operation 750). If the content identifier ID_Cont is included, the method proceeds to operations 760 and 770, and otherwise, the method proceeds to operation 780.
- the user device UD determines whether verification of the content Cont succeeds or fails by inputting the signature value S2 and the public key PK_CP of the content provider CP, and the content Cont into a verification function V() (operation 760). That is, whether the content Cont is signed using the private key SK_CP is verified.
- the verification function V() is given by:
- the user device UD determines whether the public key PK_CP of the content provider CP is valid and whether the content identifier ID_Cont has been altered by inputting the signature value S 1 and the public key PK_CA of the certificate authority CA, the content identifier ID_Cont extracted in operation 730, and the public key PK_CP into the verification function V() (operation 770).
- the verification function V() is given by Equation (16).
- the signature value Sl is obtained by electronically signing both the public key PK_CP of the content provider CP and the content identifier ID_Cont.
- V(S 1 , PK_CA, ID_ContllPK_CP) V(S(SK_CA, ID_ContllPK_CP),
- the user device UD does not authenticate the content provider CP as an authorized content provider and rejects reproduction of the content Cont. More specifically, the user device UD determines the content provider CP to be a revoked content provider when it is determined in operation 740 that the public key PK_CP is included in the revocation list RL and it is determined in operation 750 that the content identifier ID_Cont is not included in the exception list RL_C_nonRev, determines the content provider CP to disguise himself or herself as another content provider when the verification fails in operations 760 and 770, and determines that the content identifier ID_Cont has been altered when the verification fails in operation 770. In these cases, the user device UD rejects reproduction of the content Cont.
- a revocation list additionally includes a content identifier of content that is not revoked although a public key of a content provider who provides the content is included in the revocation list. Accordingly, the user device can identify an object to be revoked, and thus, it is possible to prevent a properly authorized content from being revoked.
- the content identifier ID_Cont is included in the signature value Sl of the certificate authority CA in operation 710, and verified when the signature value S 1 is verified in operation 770. Therefore, the user device UD cannot alter the content identifier ID_Cont, thereby increasing the security for the method of FIG. 7.
- a method of revoking a public key of a content provider according to the present invention can be realized as a computer program. Codes and code segments of the computer program can be easily inferred by computer programmers in the art.
- the computer program may be stored in a computer readable medium. When the computer program is read and executed by a computer, the method is realized.
- the computer readable medium may be any medium, such as a magnetic recording medium, an optical recording medium, or a carrier wave.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007545378A JP2008523703A (en) | 2004-12-10 | 2005-12-08 | How to release authority of content provider public key |
EP05821074A EP1820296A1 (en) | 2004-12-10 | 2005-12-08 | Method of revoking public key of content privider |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US63457504P | 2004-12-10 | 2004-12-10 | |
US60/634,575 | 2004-12-10 | ||
KR10-2004-0112241 | 2004-12-24 | ||
KR1020040112241A KR100823254B1 (en) | 2004-12-10 | 2004-12-24 | Method for revoking a public key of content provider |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2006062358A1 true WO2006062358A1 (en) | 2006-06-15 |
Family
ID=36578144
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/KR2005/004191 WO2006062358A1 (en) | 2004-12-10 | 2005-12-08 | Method of revoking public key of content privider |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP1820296A1 (en) |
WO (1) | WO2006062358A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2196939A1 (en) * | 2007-10-02 | 2010-06-16 | Panasonic Corporation | Copyright protection system, reproduction device, and reproduction method |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020095579A1 (en) * | 1997-06-05 | 2002-07-18 | Hiroshi Yoshiura | Digital data authentication method |
US20040037424A1 (en) * | 2002-06-24 | 2004-02-26 | International Business Machines Corporation | Information distribution and processing |
-
2005
- 2005-12-08 WO PCT/KR2005/004191 patent/WO2006062358A1/en active Application Filing
- 2005-12-08 EP EP05821074A patent/EP1820296A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020095579A1 (en) * | 1997-06-05 | 2002-07-18 | Hiroshi Yoshiura | Digital data authentication method |
US20040037424A1 (en) * | 2002-06-24 | 2004-02-26 | International Business Machines Corporation | Information distribution and processing |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2196939A1 (en) * | 2007-10-02 | 2010-06-16 | Panasonic Corporation | Copyright protection system, reproduction device, and reproduction method |
EP2196939A4 (en) * | 2007-10-02 | 2015-04-29 | Panasonic Ip Man Co Ltd | Copyright protection system, reproduction device, and reproduction method |
Also Published As
Publication number | Publication date |
---|---|
EP1820296A1 (en) | 2007-08-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11743054B2 (en) | Method and system for creating and checking the validity of device certificates | |
US10361867B2 (en) | Verification of authenticity of a maintenance means connected to a controller of a passenger transportation/access device of a building and provision and obtainment of a license key for use therein | |
KR20100091257A (en) | An entity bidirectional authentication method and system | |
EP2332091A1 (en) | Method and means for digital authentication of valuable goods | |
WO2008004525A1 (en) | Information processing device, information recording device, information processing system, program update method, program, and integrated circuit | |
US20090106548A1 (en) | Method for controlling secured transactions using a single physical device, corresponding physical device, system and computer program | |
JP2007104657A (en) | Apparatus and method for executing security function using smart card | |
EP3966997B1 (en) | Methods and devices for public key management using a blockchain | |
US20020194479A1 (en) | Method of protecting a microcomputer system against manipulation of data stored in a storage assembly of the microcomputer system | |
JP5183517B2 (en) | Information processing apparatus and program | |
US20230412400A1 (en) | Method for suspending protection of an object achieved by a protection device | |
US20060129827A1 (en) | Method of revoking public key of content provider | |
JP2009003501A (en) | Onetime password authentication system | |
US8646099B2 (en) | Midlet signing and revocation | |
WO2006062358A1 (en) | Method of revoking public key of content privider | |
CN109672526B (en) | Method and system for managing executable program | |
US8844047B2 (en) | Secure programming of vehicle modules | |
CN114036490A (en) | Security authentication method for calling plug-in software interface, USBKey driving device and authentication system | |
JP2006050355A (en) | Data reproducing apparatus, data reproducing method and data reproducing program | |
CN113641986B (en) | Method and system for realizing alliance chain user private key hosting based on SoftHSM | |
CN116189340A (en) | Entrance guard management method, system, device and medium based on PKI security authentication | |
CN106375340B (en) | Method and system for improving certificate verification security | |
CN117692185A (en) | Electronic seal using method and device, electronic equipment and storage medium | |
Steel | Towards a formal security analysis of the Sevecom API | |
Pohlmann et al. | Embedded PKI in industrial facilities |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KN KP KZ LC LK LR LS LT LU LV LY MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2005821074 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 200580042210.6 Country of ref document: CN Ref document number: 2007545378 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWP | Wipo information: published in national office |
Ref document number: 2005821074 Country of ref document: EP |