Patent ID: 9641331
Date: 2017-05-02
CPC Classifications: H04L

Claim:
1. A method for converting a conditional access content having been encrypted in order to be able to be decrypted by a first receiver, by using a first encryption mode involving a commutative combination using at least two input data, in content encrypted in order to be able to be decrypted by a second receiver using a second encryption mode involving a commutative combination using at least two input data, said first encryption mode being different from the second encryption mode, said method including the following steps: receiving, by a cryptographic module of said first receiver, said content encrypted according to the first encryption mode; choosing a first entry data of said combination of the first encryption mode, this first entry data being required for decrypting the content starting from the encrypted content and by using the first encryption mode; choosing a second entry data of said combination of the second encryption mode, this second entry data being required for encrypting the content starting from the clear content and by using the second encryption mode; inverting said first and second input data in order to: