This novel authentication and identification technique directly improves the security measures embedded in integrated circuits. Because of the individual delay characteristics inherent to each integrated circuit, they each can be specifically identified by an input sequence and the resultant unique response. These inputs and response are the secret signature individual to the circuit, known to some authentication authority, and essentially impossible to replicate. Such unique and identifiable hardware chips offer many advantages across software security applications. The identification and authentication techniques can be used for improved smartcards, unclonable with each integrated circuit’s unique secret signature key. Another application of these uniquely identifiable chips enables processor authentication so that large and distributed computations may be carried out across multiple secure chips with proof of the specific chip used and a certificate for lack of tampering. Further, for embedded intellectual property protection, a piece of code could be engineered to specifically run on a chip with the necessary secret key limiting the use of a software product or hardware intellectual property.