https://phys.org/news/2018-05-technique-counterfeit-memory.html

The problem has been further exacerbated in recent years as the semiconductor supply chain has shifted from a vertical to a horizontal model. "Because of manufacturers' enhanced reliance on independent suppliers," says Dr. Ray, "these electronic systems are at a lot more risk of counterfeiting and piracy than ever." And as counterfeiters get more and more savvy, it can be harder and harder to tell whether the components in any given electronic system are fresh or recycled – that is, he says, "until they stop working and the consumer blames the manufacturer for making a faulty product!"

At particularly high risk of counterfeiting is flash memory, a nonvolatile digital storage medium that stores data on a chip. "Flash is a major target because of its presence in the most electronic systems – it's used for everything from space applications to consumer electronics," says Dr. Ray. "But detection of recycled flash with high confidence is challenging due to the variability among different flash chips." Few feasible solutions have been proposed, however, and those that have rely on the maintenance of an extensive database or on manufacturers' willingness to adopt sensor-based approaches.