Nobody has total control over their supply chain. Substitution of counterfeit parts can happen at many points in the supply chain. Until resilient die-level traceability is universal, the best you can hope for is to minimise the risk.

FTDI do not provide any useful traceability systems. Rather than providing their customers with a reliable means to identify genuine parts, they have hugely increased the risk posed to their customers by counterfeit parts.

http://www.publicintegrity.org/2011/11/07/7323/counterfeit-c... http://spectrum.ieee.org/computing/hardware/counterfeit-chip...