Telegram does offer “secret chats,” which provides end-to-end encryption, albeit only from one device to another, between just two people. It won’t sync across multiple devices and it won’t work for groups. Telegram says this is technically difficult to do, albeit both Signal and iMessage have managed to execute this level of encryption flawlessly. In reality, Telegram’s architecture is designed to provide fast and seamless multi-device access to a cloud repository—its priorities are different. //

The Signal settings you must change are the “registration lock” and the “screen lock.” Of these, the registration lock is the critical one. This means you’ll need that PIN to install your Signal account on a new phone, stopping anyone hijacking your account. If someone does hijack your account, they won’t get access to your message history—just messages sent while they have access. This is similar to WhatsApp, albeit such hijacks have become a major issue. As Signal gains popularity, the risk will increase.