Protection method, decryption method, recording medium and terminal for said protection method
US8819436B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2011 |
| Grant date | Aug 26, 2014 |
| Priority date | — |
| Expiry date | Aug 12, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2463/101
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Protecting data transmission, either multimedia or a control word, between a security processor and a terminal includes, at the security processor, building a current session key by root key diversification as a function of a parameter transmitted by the terminal, decrypting the data, encrypting it with the session key, and transmitting it, and at the terminal, decrypting it using a secret code to obtain plain data, recording, in advance, secret codes, each enabling decryption of only data encrypted by a corresponding session key obtained by root-key diversification with a parameter, which can be the transmitted parameter, receiving the parameter in a message that also contains the data to be decrypted by the security processor, and in response, selecting, from the secret codes, a code for decrypting the data encrypted with the session key, as a function of the parameter or another parameter in the message.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.