In a first aspect of the subject invention, a secure payment card is provided, including: a flat body, the flat body having a patterned channel in proximity to a first face of the flat body; an elongated magnetic stripe disposed on the first face of the flat body, the magnetic stripe extending along a longitudinal axis, wherein at least a portion of the channel being located under the longitudinal axis; and a magnetic fluid disposed in the channel, the magnetic fluid configured to define a readable magnetic pattern.