By default, all your chats that happen in normal conversation mode on Telegram are stored as chat on Telegram’s servers. While this happens, all conversations between the cloud server and the users are encrypted.
However, what you should know is that this is not user-to-user encryption, and therefore, poses a risk of a potential breach. So if you want a way that ensures your conversations with another Telegram user are encrypted, you need to use what Telegram calls Secret Chat.
Conversations taking place in secret chat are user-to-user encrypted and not saved on the company’s servers. Moreover, these conversations can not be forwarded to another user and also prohibit screenshots.
You can also self-destruct secret chat messages, photos, videos, and files by setting a self-destruction timer — the time after which they get deleted once the recipient reads or opens them.
To start a secret chat on Android, click on the pencil icon on the home page, and select New Secret Chat. On the next page, pick the contact you want to have a secret chat with and start your conversation.
Alternatively, if you already have a chat with that user, you can tap on their profile and on the three-dot menu, and from here, select Start Secret Chat.
On the other hand, if you are an iOS user, you need to select the user with whom you want to have a secret chat and go into their profile. Here, you need to click on the three-dot button that says More and select Start Secret Chat from the options.
