DS28C39 DeepCover Secure Authenticator Analog Devices Inc. DS28C39 DeepCover Secure Authenticator is an ECDSA public-key-based bidirectional secure authenticator incorporating the patented ChipDNA™ feature. The ChipDNA has a physically unclonable function (PUF) to provide a cost-effective solution with the ultimate protection against security attacks. Using the random variation of semiconductor device characteristics that naturally occur during wafer fabrication, the ChipDNA circuit generates a unique output value that is repeatable over time, temperature, and operating voltage. Attempts to probe or observe ChipDNA operation modify the underlying circuit characteristics, preventing the discovery of the unique value used by the chip's cryptographic functions.