  Detection of counterfeit chips has emerged as a crucial concern.
Physically-unclonable-function (PUF)-based techniques are widely used for
authentication, however, require dedicated hardware and large signature
database. In this work, we show intrinsic & database-free authentication using
back-end capacitors. The discussed technique simplifies authentication setup
and reduces the test cost. We show that an analog-to-digital converter (ADC)
can be modified for back-end capacitor-based authentication in addition to its
regular functionality; hence, a dedicated authentication module is not
necessary. Moreover, since back-end capacitors are quite insensitive to
temperature and aging-induced variations than transistors, the discussed
technique result in a more reliable authentication than transistor PUF-based
authentication. The modifications to conventional ADC incur 3.2% power overhead
and 75% active-area overhead; however, arguably, the advantages of the
discussed intrinsic & database-free authentication outweigh the overheads. Full
version of this article is published at IEEE TVLSI.
