When a user starts a Secret Chat on Telegram, the app generates a special encryption key for each conversation. This key is designed to be both symmetric and end-to-end encrypted, meaning that the encryption and decryption processes are the same, and the encryption key is never shared with Telegram or any other parties. This prevents hackers, the government, or even Telegram itself from accessing the conversation, no matter if the users are connected to the internet or not.

One of the most significant advantages of Secret Chats is that the encryption keys are deleted once the conversation is over. This implies that the conversation content is deleted from Telegram's servers once the conversation is completed. However, users should note that they can save chat content manually before ending the conversation. Users should also be aware that if a user saves the chat history, they can later access the conversation content, even though the encryption keys have been deleted.

Another key point about Telegram's Secret Chats is that they prevent screenshot taking of messages. This implies that the recipient of a Secret Chat cannot take a screenshot of an incoming message. This feature has practical applications in businesses, educational institutions, or even personal relationships where sensitive information is being shared.

However, it's worth noting that Secret Chats are not the same as Telegram's other end-to-end encryption feature, 飞机中文包 the "Fast Chat" feature introduced in Telegram v5.9 and up. When a Secret Chat is enabled, it generates an 'end-to-end encrypted' identifier. This ID is saved to the conversation history; this could potentially let Telegram out. So, if you may think 'they can't see,' think one more time before saving your 'end-to-end encrypted' identifier - it has advantages and disadvantages. Therefore, proceed with caution when using this feature.

In conclusion, Telegram's Secret Chat feature is a powerful tool for users seeking end-to-end encrypted and private conversations. The feature provides a high level of security and peace of mind for users, ensuring their conversations remain private and secure. However, users should be aware of the potential risks and limitations associated with Secret Chats and use them responsibly.