Memory structure for self-erasing secret storage

In one embodiment, memory cell includes a control gate, a floating gate, a substrate comprising a source region and a drain region, a first isolator between the control gate and floating gate, and a second isolator between the floating gate and the substrate. The memory cell is configured to have a retention time that is within a statistical window around a selected lifespan. The selected lifespan may be less than ten years, such as, for example, less than one year, less than one month, or less than one week.