WhatsApp was alleged to be widely used to spread misinformation and\npropaganda during elections in Brazil and India. Due to the private encrypted\nnature of the messages on WhatsApp, it is hard to track the dissemination of\nmisinformation at scale. In this work, using public WhatsApp data, we observe\nthat misinformation has been largely shared on WhatsApp public groups even\nafter they were already fact-checked by popular fact-checking agencies. This\nrepresents a significant portion of misinformation spread in both Brazil and\nIndia in the groups analyzed. We posit that such misinformation content could\nbe prevented if WhatsApp had a means to flag already fact-checked content. To\nthis end, we propose an architecture that could be implemented by WhatsApp to\ncounter such misinformation. Our proposal respects the current end-to-end\nencryption architecture on WhatsApp, thus protecting users' privacy while\nproviding an approach to detect the misinformation that benefits from\nfact-checking efforts.\n