Electronic transaction method and system via portable accessory

The invention relates to a method for carrying out an electronic transaction between a main communication apparatus (1, 10) and a transaction terminal (3), characterized in that: a smart portable accessory (2, 12) is provided, which has a different format from a standardized chip card format and is capable of relaying the transaction or of representing said main apparatus relative to a transaction terminal; and the transaction is carried out by only presenting said accessory, instead of the main apparatus, to the transaction terminal. The invention also relates to the corresponding system. 本发明着重于种用于在通信主装置（1，10）与交易终端（3）之间实现电子交易的方法，其特征在于：-提供智能便携式配件（2，12），智能便携式配件（2，12）具有与芯片卡标准化形式不同的形式，适于中继交易或面对交易终端而代表所述主装置，-通过代替所述主装置而仅将所述配件呈现于交易终端来实现交易。本发明还涉及对应的系统。