Method for protecting decryption keys in a decoder and decoder for implementing said method
US10075770B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 4, 2014 |
| Grant date | Sep 11, 2018 |
| Priority date | — |
| Expiry date | Mar 5, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4408
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Method for securing control words within a decoder in charge of descrambling digital content protected by these control words, comprising the following steps: for each descrambling unit of this decoder, loading in a directory a pairing key referenced by an identifier associating said key to a descrambling unit; receiving at least one encrypted control word referenced by an indication allowing to identify the descrambling unit for which it is intended; decrypting the control word by using a first key shared with a security module; identifying in the directory the pairing key whose identifier corresponds to the indication of destination associated to the control word; encrypting this control word by using this pairing key; and storing in a register the control word in a chronological and referenced way.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.