A secure card such as a credit card having a magnetic strip thereon is disclosed. The magnetic strip is coated with a thin amorphous layer having electrical characteristics and a processor. In a first state, the amorphous layer acts to interfere with reading of information from the magnetic strip. Identification of a user of the card as an authorized user thereof results in a second state in which the information stored in the magnetic strip is accessible. For example, biometric identification or the use of a PIN entered either directly into the card or through an input terminal cause the processor to switch power from the amorphous strip thereby removing the interference and unmasking the information on the magnetic strip.