A smartwatch comprising: a housing ; a display ; an antenna ; a crown of the smartwatch configured to be retracted from the housing and configured to be rotated; processing logic coupled to the display to drive the display , wherein the processing logic is coupled to the antenna to send and receive wireless signals via the antenna ; and a computer readable medium accessible to the processing logic , the computer readable medium including instructions, executable by the processing logic to cause the processing logic to: transmit, by the antenna , transaction details to a contactless transaction module; perform a component of a transaction authorization process with an application (17A-D) of the smartwatch characterized by : adjusting a time depicted on an analog clock interface rendered to the display in response to sensing a rotation of the crown of the smartwatch ; upon signalizing the completion of the rotation of the crown , determining a specific time depicted on the analog clock interface; and transmitting, by the antenna , the specific time to the contactless transaction module in response to selection of the specific time by a user of the smartwatch , wherein the specific time acts as authentication information of the user to complete the transaction authorization process. a housing ; a display ; an antenna ; a crown of the smartwatch configured to be retracted from the housing and configured to be rotated; processing logic coupled to the display to drive the display , wherein the processing logic is coupled to the antenna to send and receive wireless signals via the antenna ; and a computer readable medium accessible to the processing logic , the computer readable medium including instructions, executable by the processing logic to cause the processing logic to: transmit, by the antenna , transaction details to a contactless transaction module; perform a component of a transaction authorization process with an application (17A-D) of the smartwatch characterized by : adjusting a time depicted on an analog clock interface rendered to the display in response to sensing a rotation of the crown of the smartwatch ; upon signalizing the completion of the rotation of the crown , determining a specific time depicted on the analog clock interface; and transmitting, by the antenna , the specific time to the contactless transaction module in response to selection of the specific time by a user of the smartwatch , wherein the specific time acts as authentication information of the user to complete the transaction authorization process. transmit, by the antenna , transaction details to a contactless transaction module; perform a component of a transaction authorization process with an application (17A-D) of the smartwatch characterized by : adjusting a time depicted on an analog clock interface rendered to the display in response to sensing a rotation of the crown of the smartwatch ; upon signalizing the completion of the rotation of the crown , determining a specific time depicted on the analog clock interface; and transmitting, by the antenna , the specific time to the contactless transaction module in response to selection of the specific time by a user of the smartwatch , wherein the specific time acts as authentication information of the user to complete the transaction authorization process. adjusting a time depicted on an analog clock interface rendered to the display in response to sensing a rotation of the crown of the smartwatch ; upon signalizing the completion of the rotation of the crown , determining a specific time depicted on the analog clock interface; and transmitting, by the antenna , the specific time to the contactless transaction module in response to selection of the specific time by a user of the smartwatch , wherein the specific time acts as authentication information of the user to complete the transaction authorization process. <EOS>