PALs, a form of programmable logic, can be studied by extracting an original or equivalent programming file. Then it shows an alternate technique using microscopy to extract the original bitstream. Finally the microscope technique is extended to aid microprobing security circuitry.
John McMaster is hardware reverse engineer with a decade of embedded security expertise. He specializes in microcontroller data extraction using lasers, microscopes, and power analysis. Twitter: @johndmcmaster