While WhatsApp later added Signal Protocol-based encryption in 2016, version 2.11.431 used a simpler, less secure form of encryption. The app never nagged you with "Your chats are end-to-end encrypted" banners. It simply worked.
If you actually want to or need assistance with a specific text creation task (like a fake chat for testing or writing), please clarify, and I'll help you directly. whatsapp 2.11.431
It stands as a historical marker for when digital etiquette on WhatsApp changed forever. version 2.11.431 used a simpler