Integrated circuits are typically fabricated using the same lithography masks, and are often identified by embedding a unique identifier in the chip, such as a serial number. The main issue with this current security technology is its replicability. It is possible to clone these chips and their key information if another party gains possession for even a short period of time. Thus, when the original user regains possession, there could exist an exact copy of the chip.
With the novel identification and authentication techniques enabled by secret signatures, a hardware chip virtually cannot be replicated with the same delay characteristic, and therefore ensures the safety of the potential smartcard, software IP, or processor. An opposing party would require prolonged physical access to the hardware chip along with highly specific and expensive technology to replicate the minute fabrication variations unique to the chip. To totally prevent any opposing party from creating an exact copy of an integrated circuit, detection depends on a complete and precise timing characterization of the original circuit, an intractable task.