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. The Russian invasion of Ukraine has been a driving force in markets for the past few weeks. If you initiate a Secret Chat, however, then these communications are end-to-end encrypted and are tied to the device you are using. That means it’s less convenient to access them across multiple platforms, but you are at far less risk of snooping. Back in the day, Secret Chats received some praise from the EFF, but the fact that its standard system isn’t as secure earned it some criticism. If you’re looking for something that is considered more reliable by privacy advocates, then Signal is the EFF’s preferred platform, although that too is not without some caveats. Some privacy experts say Telegram is not secure enough "There is a significant risk of insider threat or hacking of Telegram systems that could expose all of these chats to the Russian government," said Eva Galperin with the Electronic Frontier Foundation, which has called for Telegram to improve its privacy practices.
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