When you send photos, videos or files via secret chats, before being uploaded, each item is encrypted with a separate key, not known to the server. This key and the file’s location are then encrypted again, this time with the secret chat’s key — and sent to your recipient. They can then download and decipher the file. This means that the file is technically on one of Telegram’s servers, but it looks like a piece of random indecipherable garbage to everyone except for you and the recipient. We don’t know what this random data stands for and we have no idea which particular chat it belongs to. We periodically purge this random data from our servers to save disk space.</p> <i>