A method of secure reception, in a card reader, of a piece of data entered into a terminal connected to the card reader. The method includes the following acts by the card reader: obtaining an encipherment reader key from the card reader; encrypting the encipherment reader key by using an authentic encipherment key shared between the card reader and an authentication server, delivering an encrypted reader key; sending the encrypted reader key to the authentication server for transmission of the reader key from the authentication server to the terminal; receiving an encrypted key sent by the authentication server, resulting from an encryption of a terminal key, obtained by the authentication server, by using the authentic key; and receiving encrypted data sent by the terminal, resulting from an encryption, by using at least the reader key and of the terminal key, of the at least one piece of data.