On Rumors About Telegram Servers in Weird Places

There are some reports that the Iranian Minister of Communication Mahmoud Vaezi said that "Telegram moved some of its servers to Iran". Since there are no Telegram servers in Iran, this is probably another piece of fake news or incorrect translation. But if the Iranian Minister did say something like this, he probably referred to one of the CDN caching nodes that Telegram rents from a global CDN-provider to cache publicly available data locally in many places of the world where we don't wan't to install our own servers (e.g. Turkey, Iraq, Iran, India, Indonesia or Argentina).

As we pointed out when we started to support CDN caching, such local nodes don't include any Telegram servers and can't store any private data. These are pieces of rented infrastructure that we and other companies rely on to deliver data more efficiently to users all over the world.  It is always misleading to refer to CDN nodes as Telegram servers, but as I noted in my recent Telegram post, politicians and journalists may try this when they want to score points or get page views.

It seems that politicians / journalists sometimes refer to an internet traffic provider or a CDN provider that delivers or caches encrypted data of Telegram as “Telegram” or “Telegram servers“, thus misleading the public. There’s a world of difference between them: Telegram servers store private data and will never “travel” to countries with internet censorship, while internet providers and CDNs operate all over the world and have no access to private data of Telegram (and other secure apps).

Since even a few rented caching servers in countries like Iran or Iraq can raise questions, some time ago we posted extensive technical details about how these caching nodes work to show that no private data can even in theory be compromised by this local caching.

Anybody with an engineering background can verify the security of these caching nodes by studying the source code of the Telegram apps, using traffic inspection tools or studying our docs that describe how encryption and integrity checks are guaranteed. Here are the links to the detailed info I provided in my channel:

To avoid confusion, here are some points from the summary we posted when we started to support CDN caching nodes globally:

• Download speed for popular public media is set to increase several times for millions of Telegram users.
• CDN caching nodes are not Telegram servers and not part of the Telegram cloud.
• CDNs are used only for caching popular public media from massive channels. Private data never goes there.
• CDNs only get encrypted data and they never have the keys: even if they are accessed by hackers or third parties, the attacker won’t be able to decipher the files.
• Data downloaded from CDN caching nodes is always verified by the receiving Telegram app by way of hash: attackers won’t be able to replace any files with their own versions.
• Detailed technical info about CDNs can be found here, the updated source code of Telegram apps ready for CDN support can be found here.

Those who read all my posts might already know all of the above, but I decided to summarize everything CDN-related here in a Telegraph post to avoid confusion as a result of incorrect translations or inaccurate claims. If you ever read a story/post/tweet that claims Telegram servers moved to some weird place, please help us by sharing this post and spreading the word.