  The recent advancements in Generative Adversarial Networks (GANs) and the
emergence of Diffusion models have significantly streamlined the production of
highly realistic and widely accessible synthetic content. As a result, there is
a pressing need for effective general purpose detection mechanisms to mitigate
the potential risks posed by deepfakes. In this paper, we explore the
effectiveness of pre-trained vision-language models (VLMs) when paired with
recent adaptation methods for universal deepfake detection. Following previous
studies in this domain, we employ only a single dataset (ProGAN) in order to
adapt CLIP for deepfake detection. However, in contrast to prior research,
which rely solely on the visual part of CLIP while ignoring its textual
component, our analysis reveals that retaining the text part is crucial.
Consequently, the simple and lightweight Prompt Tuning based adaptation
strategy that we employ outperforms the previous SOTA approach by 5.01% mAP and
6.61% accuracy while utilizing less than one third of the training data (200k
images as compared to 720k). To assess the real-world applicability of our
proposed models, we conduct a comprehensive evaluation across various
scenarios. This involves rigorous testing on images sourced from 21 distinct
datasets, including those generated by GANs-based, Diffusion-based and
Commercial tools.
