Patent ID: 9294273
Filing Date: 2016-03-22
CPC Classification: H04L

Claim Text:
1. A method for generating a control word, said method being implemented by a processor of a subscriber electronic device cooperating with a terminal, said device comprising an interface for receiving data from the terminal and for delivering said generated control word to the terminal, said method comprising: receiving, by the interface, data that comprise a tag t, wherein the tag t includes data identifying a current cryptoperiod; determining, by a processor, the current cryptoperiod by using the identifying data included in the received tag t; generating, by the processor, a control word from said current cryptoperiod cp and a secret SK delivering a control word k′ using the interface of the subscriber electronic device; wherein: delivering the control word comprises delivering k′ equal to k the control word is generated such that the terminal is configured to use the control word to decode an encoded content C and generate plain text M of the content by receiving the control word and a header H by: