Telegram is a communication service. You provide your mobile number and basic account data (which may include profile name, profile picture and about information) to create a Telegram account.
To make it easier for your contacts and other people to reach you and recognize who you are, the screen name you choose, your profile pictures, and your username (should you choose to set one) on Telegram are always public. We don't want to know your real name, gender, age or what you like.
We do not require your screen name to be your real name. Note that users who have you in their contacts will see you by the name they saved and not by your screen name. This way your mother can have the public name ‘Johnny Depp’ while appearing as ‘Mom’ to you and as ‘Boss’ to her underlings at work (or the other way around, depending on how these relationships are structured).
When you enable 2-step-verification for your account or store documents using the Telegram Passport feature, you can opt to set up a password recovery email. This address will only be used to send you a password recovery code if you forget it. That's right: no marketing or “we miss you” bullshit.
Telegram is a cloud service. We store messages, photos, videos and documents from your cloud chats on our servers so that you can access your data from any of your devices anytime without having to rely on third-party backups. All data is stored heavily encrypted and the encryption keys in each case are stored in several other data centers in different jurisdictions. This way local engineers or physical intruders cannot get access to user data.
Secret chats use end-to-end encryption. This means that all data is encrypted with a key that only you and the recipient know. There is no way for us or anybody else without direct access to your device to learn what content is being sent in those messages. We do not store your secret chats on our servers. We also do not keep any logs for messages in secret chats, so after a short period of time we no longer know who or when you messaged via secret chats. For the same reasons secret chats are not available in the cloud — you can only access those messages from the device they were sent to or from.
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.
In addition to private messages, Telegram also supports public channels and public groups. All public chats are cloud chats (see section 3.3.1 above). Like everything on Telegram, the data you post in public communities is encrypted, both in storage and in transit — but everything you post in public will be accessible to everyone.
Telegram uses phone numbers as unique identifiers so that it is easy for you to switch from SMS and other messaging apps and retain your social graph. We ask your permission before syncing your contacts.
We store your up-to-date contacts in order to notify you as soon as one of your contacts signs up for Telegram and to properly display names in notifications. We only need the number and name (first and last) for this to work and store no other data about your contacts.
Our automatic algorithms can also use anonymized sets of phone numbers to calculate the average number of potential contacts an unregistered phone number may have on Telegram. When you open the ‘Invite friends’ interface, we display the resulting statistics next to your contacts to give you an idea of who could benefit most from joining Telegram.
You can always stop syncing contacts or delete them from our servers in Settings > Privacy & Security > Data Settings.
If you are using Android, Telegram will ask you for permission to access your phone call logs (READ_CALL_LOG). If you grant this permission, Telegram will be able verify your account by transmitting a phone call instead of asking you to enter a code. Telegram uses this permission only to confirm receipt of the confirmation call by verifying the number in the call log.