Content delivery system and content delivery method
First Claim
1. A content delivery system comprising:
- a user device which transmits a content-purchasing request to a shop server;
a shop server which receives the content-purchasing request from the user device and which manages an encrypted content encrypted using a content key Kc and also manages an encrypted content key which cannot be decrypted by a key stored in the user device; and
a user device authentication server for performing a key conversion process so as to convert the encrypted content key into a form which can be decrypted using the key stored in the user device;
wherein if a process for charging the fee for the content purchased by the user device has been completed, the encrypted content key converted by the user device authentication server into the form which can be decrypted by the key stored in the user device is provided by the shop server to the user device.
5 Assignments
0 Petitions
Accused Products
Abstract
In a content delivery system, delivery of a content and charging for the fee of the content are performed and managed in a highly secure and effective fashion. If a content-purchasing request is transmitted from a user device to a shop server, a charging process is performed. If the charging process is successfully completed, the shop server transmits, to the user device, an encrypted content key in a form which can be decrypted by a key stored in the user device. A user device authentication server, which manages content delivery, converts an encrypted content key KpDAS(Kc) encrypted using a public key of the user device authentication server (DAS) into an encrypted content key KpDEV(Kc) encrypted using a public key KpDEV of the user device. Provided that the charging process has been successfully completed in response to the content-purchasing request, the shop server transmits the key-converted content key to the user device.
176 Citations
18 Claims
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1. A content delivery system comprising:
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a user device which transmits a content-purchasing request to a shop server;
a shop server which receives the content-purchasing request from the user device and which manages an encrypted content encrypted using a content key Kc and also manages an encrypted content key which cannot be decrypted by a key stored in the user device; and
a user device authentication server for performing a key conversion process so as to convert the encrypted content key into a form which can be decrypted using the key stored in the user device;
wherein if a process for charging the fee for the content purchased by the user device has been completed, the encrypted content key converted by the user device authentication server into the form which can be decrypted by the key stored in the user device is provided by the shop server to the user device. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A user device authentication server which manages delivery of a content sold between a shop server and a user device,
wherein in response to receiving a key conversion request from the shop server or the user device, the user device authentication server converts a content key associated with the content sold between the shop server and the user device, from an encrypted form which cannot be decrypted by a key stored in the user device into an encrypted form which can be decrypted by the key stored in the user device, and wherein the user device authentication server verifies a digital signature of the shop server or a digital signature of the user device written in the key conversion request, and the user device authentication server performs the key conversion, if the verification indicates that the key conversion request is valid.
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9. A shop server which provides, to a user device, a content key used to decrypt an encrypted content,
wherein the shop server stores a content key used to encrypt the content in such a manner that the content key used to encrypt the content is encrypted into a form which cannot be decrypted by a key stored in the user device, and wherein if the charging process in response to the content-purchasing request issued by the user device has been successfully completed, the shop server transmits, to the user device, the encrypted content key which has been generated via a key conversion process performed by a user device authentication server, which manages content delivery, such that the encrypted content key in the form which cannot be decrypted by the key stored in the user device is converted into a form which can be decrypted by the key stored in the user device.
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11. A content reproducing device which generates a content-purchasing request, transmits it to a shop server, and reproduces a content,
wherein the content reproducing device acquires a content key by performing a process including the steps of: -
receiving, via a shop server, an encrypted content key which has been generated via a key conversion process performed by a user device authentication server, which manages content delivery, such that an encrypted content key in a form which cannot be decrypted by a key stored in the content reproducing device is converted into a form which can be decrypted by the key stored in the content reproducing device;
verifying signatures, included in the received encrypted content key data, of the shop server and the user device authentication server; and
if the verification indicates that the data has not been tampered with, extracting the encrypted content key from the received encrypted content key data, thereby acquiring the content key. - View Dependent Claims (13, 14, 15, 16, 17)
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12. A content delivery method comprising the steps of:
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transmitting a content-purchasing request from a user device to a shop server;
receiving, at the shop server, the content-purchasing request from the user device;
in a user device authentication server, converting an encrypted content key in a form which cannot be decrypted by a key stored in the user device into an encrypted content key in a form which can be encrypted by the key stored in the user device; and
if the user device has completed a charging process associated with the purchasing of a content, providing, from the shop server to the user device, the encrypted content key converted by the user device authentication server into the form which can be decrypted by the key stored in the user device.
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18. A program providing medium for providing a computer program executable on a computer system to perform a content key delivery process, the computer program comprising the steps of:
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receiving an encrypted content key, generated by a user device authentication server, which manages content delivery, into a form capable of being decrypted by a key stored in a user device;
performing a charging process on the basis of the content-purchasing request issued by the user device; and
if the charging process has been successfully completed, transmitting, to the user device, the encrypted content key in the form capable of being decrypted by the key stored in the user device.
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Specification