A secure transaction system includes an image generator configured to generate human readable characters, a random placement generator coupled to the image generator, and an encoding system configured to encode the human readable characters in a data stream in an order determined by the placement generator, wherein the transaction system is configured to transmit the data stream to a user interface and to receive a selected data stream from the user interface. Also included is a method for secure transaction processing including receiving an encoded data stream representative of a plurality of human readable characters positioned in a random order, selecting a human readable character from the plurality of human readable characters, and transmitting a portion of an encoded data stream representative of the selected human readable character.