Method for transmitting data, implemented within a secured execution environment of an electronic device, called a trusted component, said trusted component being coupled to a cash register (CRA, DEC), said method of data transmission comprising the following steps: - a step for receiving, from the cash register (DEC, CRA), a first request (RSC#1) for setting up a first secured communications channel (SC#1) with said trusted component; - a step for setting up said first secured communications channel (SC#1) between the trusted component and the cash register, by means of at least an identifier of said cash register contained in said first request (RSC#1), after a first positive step of searching, within an authorization data structure previously provided in the trusted component, for a piece of data corresponding to said identifier of said cash register; - a step for receiving, from a payment terminal (PERIPH, TERMP), a second request (RSC#2) for setting up a second secured communications channel (SC#2) with said trusted component; - a step for setting up said second secured communications channel (SC#2), between said trusted component and said payment peripheral (PERIPH, TERMP) by means of at least an identifier of the payment terminal, contained in said second request, after a second positive step of searching, within the authorization data structure, for a piece of data corresponding to said identifier of said payment terminal; - a step for transmitting, by the payment terminal, a piece of data intended for said cash register comprising decrypting by the trusted component said piece of data from the second secured communications channel, re-encrypting and sending the piece of data on the first secured communications channel. - a step for receiving, from the cash register (DEC, CRA), a first request (RSC#1) for setting up a first secured communications channel (SC#1) with said trusted component; - a step for setting up said first secured communications channel (SC#1) between the trusted component and the cash register, by means of at least an identifier of said cash register contained in said first request (RSC#1), after a first positive step of searching, within an authorization data structure previously provided in the trusted component, for a piece of data corresponding to said identifier of said cash register; - a step for receiving, from a payment terminal (PERIPH, TERMP), a second request (RSC#2) for setting up a second secured communications channel (SC#2) with said trusted component; - a step for setting up said second secured communications channel (SC#2), between said trusted component and said payment peripheral (PERIPH, TERMP) by means of at least an identifier of the payment terminal, contained in said second request, after a second positive step of searching, within the authorization data structure, for a piece of data corresponding to said identifier of said payment terminal; - a step for transmitting, by the payment terminal, a piece of data intended for said cash register comprising decrypting by the trusted component said piece of data from the second secured communications channel, re-encrypting and sending the piece of data on the first secured communications channel.