System and method for enhanced piracy protection in a wireless personal communication device
First Claim
1. A method of controlling content usage in a personal communication device, comprising:
- receiving a first and second key-share, encrypted content, and a set of measurement parameters over a communication link in response to a request to access the encrypted content and verification of a credit; and
combining at least the first key-share, the second key-share that is received from a finance server when the credit is verified, and a device-dependent key-share that is pre-stored in the personal communication device, to generate a decryption key to decrypt the encrypted content.
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Accused Products
Abstract
A key-sharing scheme is used to control distribution and use of video and audio content in personal digital assistants (PDAs) and other wireless devices. A private key is split into key-shares using a Blakley-Shamir key splitting technique and the key-shares are distributed to various network entities including a finance server and security server. Key-shares are also stored in a user'"'"'s subscriber identity module (SIM) and a security processor of the PDA. The key-shares from the network entities are provided to the PDA after the user requests specific video or audio content and credit verification is performed. The PDA'"'"'s security processor combines the key-shares to form the decryption key for use in playing the content by the PDA'"'"'s communications processor. When a service limit is reached, the PDA'"'"'s security processor purges the key-shares to prevent further use of the content.
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Citations
21 Claims
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1. A method of controlling content usage in a personal communication device, comprising:
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receiving a first and second key-share, encrypted content, and a set of measurement parameters over a communication link in response to a request to access the encrypted content and verification of a credit; and combining at least the first key-share, the second key-share that is received from a finance server when the credit is verified, and a device-dependent key-share that is pre-stored in the personal communication device, to generate a decryption key to decrypt the encrypted content. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of controlling content usage in a personal communication device using a decryption key that is divided into a plurality of key-shares, the method comprising:
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providing to the personal communication device a first key-share and a set of measurement parameters in response to a request for content; and verifying a credit by a finance server in communication with the personal communication device; providing to the personal communication device a second key-share when the credit is verified by the finance server; and combining the first and second key-shares with a third key-share that is device dependent and pre-stored in the personal communication device for use in decrypting the content. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of controlling content usage in a personal communication device, comprising:
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receiving a first and second key-share, encrypted content, and a set of measurement parameters over a communication link in response to a request to access the encrypted content and verification of a credit; and combining at least the first key-share, the second key-share that is held by a security server until the credit is verified by a finance server and a device-dependent key-share that is pre-stored in the personal communication device, to generate a decryption key to decrypt the encrypted content.
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21. A method of controlling content usage in a personal communication device, comprising:
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receiving a first and second key-share, encrypted content, and a set of measurement parameters over a communication link in response to a request to access the encrypted content and verification of a credit; and combining at least the first key-share, the second key-share that is received from a finance server when the credit is verified, and a device-dependent key-share that is generated by a security server and provided to the personal communication device, to generate a decryption key to decrypt the encrypted content.
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Specification