Systems and methods of generating a security key for an integrated circuit device include generating a plurality of key bits with a physically unclonable function (PUF) device. The PUF can include a random number generator that can create random bits. The random bits may be stored in a nonvolatile memory. The number of random bits stored in the nonvolatile memory allows for a plurality of challenge and response interactions to obtain a plurality of security keys from the PUF.