Right now the digital security needs of Russians and Ukrainians are very different, and they lead to very different caveats about how to mitigate the risks associated with using Telegram. For Ukrainians in Ukraine, whose physical safety is at risk because they are in a war zone, digital security is probably not their highest priority. They may value access to news and communication with their loved ones over making sure that all of their communications are encrypted in such a manner that they are indecipherable to Telegram, its employees, or governments with court orders. The fake Zelenskiy account reached 20,000 followers on Telegram before it was shut down, a remedial action that experts say is all too rare. However, the perpetrators of such frauds are now adopting new methods and technologies to defraud the investors. But the Ukraine Crisis Media Center's Tsekhanovska points out that communications are often down in zones most affected by the war, making this sort of cross-referencing a luxury many cannot afford. 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.
from de