Telegram does offer end-to-end encrypted communications through Secret Chats, but this is not the default setting. Standard conversations use the MTProto method, enabling server-client encryption but with them stored on the server for ease-of-access. This makes using Telegram across multiple devices simple, but also means that the regular Telegram chats you’re having with folks are not as secure as you may believe. But Kliuchnikov, the Ukranian now in France, said he will use Signal or WhatsApp for sensitive conversations, but questions around privacy on Telegram do not give him pause when it comes to sharing information about the war. Russians and Ukrainians are both prolific users of Telegram. They rely on the app for channels that act as newsfeeds, group chats (both public and private), and one-to-one communication. Since the Russian invasion of Ukraine, Telegram has remained an important lifeline for both Russians and Ukrainians, as a way of staying aware of the latest news and keeping in touch with loved ones. In 2018, Russia banned Telegram although it reversed the prohibition two years later. Such instructions could actually endanger people — citizens receive air strike warnings via smartphone alerts.
from it
