Network on Chip Security - Without secure wrappers, it is impossible to protect the integrity of embedded IP cores for NoC-based SoC. This paper describes an IEEE 1500 compatible secure test wrapper NoC based on low-cost PUF circuit. The original key generated by LFSR is encrypted into a stream cipher by the PUF module, and the input key string should be equal to this cryptograph unless the wrapper is locked, which provides effective on-line authentication.