In high security devices, like smart cards, the on-board software may be embedded in ROM (read only memory). But, based on flexibility arguments, non-volatile flash memory based software storage can be more preferred. This invention describes a method to recover from a situation of data loss on flash devices by combining the on-device available secure boot-loading with embedded physical unclonable functions (PUF), where the PUF provides the cryptographic key for starting the data recovery procedure.