Abstract: Various embodiments consistent with the invention relate to a secure electronic entity including a communications interface, the entity being characterized in that it includes means that act, when it is connected via said communications interface to a portable electronic device, including means for connection to a telecommunications network, to enable it: to authenticate a remote transaction verification server in the telecommunications network and to authenticate itself with said remote server; to establish a secure connection, via the telecommunications network, with said remote server; and to receive, via said communications interface, data relating to an intended transaction with a third party device, and to transmit that data, via the secure connection, to the remote server so that it can analyze the data in order to take a decision as to whether to authorize the transaction.