A method is provided for authentication between a mobile terminal, located less than a predefined distance from the body of a user, and a processing terminal. The mobile terminal includes an antenna constituting a radio interface suitable for transmitting and receiving radio signals through the body of the user, and the processing terminal is suitable for transmitting and receiving radio signals through the body of the user. The method includes: approaching a user interface of the processing terminal with a portion of the body, triggering an activation of the processing terminal and establishing communication between the processing terminal and the mobile terminal; requesting the entering of a piece of personal authentication data; memorizing the authentication data entered; sending the authentication data through the body; receiving a result of a check of the authentication data carried out by the terminal; and checking the result.

Disclosed is a method performed in a system comprising a first Body Area Network (BAN) enabled device and a second BAN enabled device, for performing secure payment at a payment counter by a user of the first and the second BAN enabled devices, the user wearing or carrying the first and the second BAN enabled devices; where the first and the second BAN enabled devices are paired for authorizing the user by the second BAN enabled device; the method comprises: establishing a connection between the payment counter and the first BAN enabled device; sending a BAN signal via BAN from the first BAN enabled device to the second BAN enabled device requiring confirmation from the second BAN enabled device that the second BAN enabled device is in contact with the user's body; receiving a confirmation BAN signal via BAN from the second BAN enabled device to the first BAN enabled device confirming that the second BAN enabled device is in contact with the user's body; receiving a request for payment from the payment counter in the first and/or second BAN enabled device; and confirming the requested payment in the first and/or second BAN enabled device.