Physically Unclonable Function using Initial Waveform of Ring Oscillators
This is an incremental improvement for implementing PUFs in local devices by addressing power and time constraints.
The paper tackles the high power consumption and long ID generation time in conventional ring oscillator physically unclonable functions (RO-PUFs) by using the initial waveform of ring oscillators instead of frequency differences, reducing the number of ROs needed and finishing ID generation in a couple of system clocks.
A silicon physically unclonable function (PUF) is considered to be one of the key security system solutions for local devices in an era in which the internet is pervasive. Among many proposals, a PUF using ring oscillators (RO-PUF) has the advantage of easy application to FPGA. In the conventional RO-PUF, frequency difference between two ROs is used as one bit of ID. Thus, in order to obtain an ID of long bit length, the corresponding number of RO pairs are required and consequently power consumption is large, leading to difficulty in implementing RO-PUF in local devices. Here, we provide a RO-PUF using the initial waveform of the ROs. Because a waveform constitutes a part of the ID, the number of ROs is greatly reduced and the time needed to generate the ID is finished in a couple of system clocks. We also propose a solution to a change of PUF performance attributable to temperature or voltage change.