Telegram working despite ban, raises doubts on India's tech ability to block it

India on Tuesday banned Telegram ahead of the NEET re-test on June 21. But hours after this ban, the app continues to largely work. It casts doubt on India's ability to block Telegram, which has some inbuilt tech safeguards against censorship and ban.

In Short

• Telegram still working in India despite ban, users say
• It is possible that blocking Telegram could be tricky
• Telegram cannot be blocked the way TikTok was blocked

India banned Telegram on Tuesday ahead of the NEET re-test scheduled for June 21. The ban is expected to last until June 22. On the surface, it seems like a simple ban, similar to what has happened with various apps in India before, including TikTok and PUBG. But, hours later, Telegram continues to be accessible India. The app is still working as it works, the Telegram website is still up and running, and t.me — the domain through which Telegram serves messages on web — still accessible.

Update: The app has been removed from Google Play Store, and will likely soon be removed from the iOS App Store. Although, this doesn't matter that much because Telegram remains widely available on tens of different app stores on the web, and through APKs.

Now there is chatter online that India may not succeed in putting a blanket ban on Telegram because the country does not have the technology at ISP level to block it. This is because Telegram has a number of technologies that it uses to evade bans and censorship. Or to put it another way, blocking Telegram could prove to be tricky.

Nisarga Adhikary, the 19-year-old cybersecurity researcher who went viral after exposing flaws in CBSE’s website, claims this ban may not even be possible. He wrote on X, “Blocking Telegram totally isn't even possible, Telegram is designed in such a way which easily allows people to use proxies and other methods of circumvention.”

India usually bans stuff with DNS blocking

Usually, when Indian government orders a ban on a website or app, the responsibility falls on Internet Service Providers (ISPs) like Jio or Airtel. These companies, which run the network, block websites or apps based on what you search for.

Normally when you search for a website, say Instagram, the request goes to your ISP’s Domain Name System (DNS) which acts like the phonebook for the internet. The DNS then tells your phone where Instagram is, and lets you connect to it.

Similarly, when an ISP is blocking a website, such as TikTok, the DNS at ISP level refuses to look for the app servers. Instead, lies to the user that TikTok is not accessible. This leaves your device with no way to connect to the platform. Keep in mind that this is not the only way to block a website, but it is the most common.

So why is Telegram different?

On X, a user who goes by the handle @kingslyj claimed that the traditional way of blocking a platform will not work on Telegram. The user said that Telegram didn’t work like other platforms, particularly in this DNS area. The person wrote, “They cannot use current blocking infrastructure because Telegram doesn't do direct DNS lookups.”

The user claimed that Telegram operates differently. Instead of the usual way we discussed before, Telegram sends encrypted requests to cloud servers, such as Cloudflare and Google. This means that your internet service provider will not know what you were requesting for. And as a result, it won’t be able to block you from accessing Telegram.

The user claimed that while there can other ways to block Telegram, India may not have the tech infrastructure it needs to do so. The person added, “Existing infra (of Indian ISPs) isn't capable of dealing with that.”

Why is blocking Telegram tricky?

Now, DNS-level blocking is not the only way ISPs block websites and apps. They also have far more advanced tools. They can use methods like Deep Packet Inspection (DPI) to find pattern — or signature — in internet traffic, and through these signatures they can identify an app and can block it.

For example, an app like Telegram will have a particular kind of traffic pattern, indicating where the traffic is going, how much is the volume, what is its packet size etc. Similarly, there is SNI filtering, which can let ISPs see what you are trying to access before the secure (HTTPS) connection is made between your computer or phone with an app or a website.

But just the way there are different ways to block something, there are ways to avoid the ban and censorship. And Telegram, by its design, is an app that actively works to avoid bans and censorship. It does this by using an encryption technology called MTProto protocol. This protocol apparently lets the app fake its digital signature to ensure that its traffic looks like that of a normal website or app. In others words, MTProto protocol makes it difficult for DPI to sniff and single out Telegram from gigabytes of data flowing through ISP servers.

The MTProto was probably the reason why Telegram ban in Russia resulted in not just a ban on the app, but also an accidental ban on hundreds of other legitimate services and apps because ISPs could not reliably detect only Telegram traffic.

It addition to MTProto, Telegram also uses complicated routing and rerouting for its traffic. It tends to bounce its traffic through proxy servers by default, which again makes it difficult for ISPs like Jio and Airtel to reliably ban Telegram servers.

It is this strange nature of Telegram that commenters are highlighting on social media. User kingslyj, for example, wrote: “Unstated and actual reason (behind ban) is for ISPs to figure out how to effectively block Telegram. They cannot use current blocking infrastructure because Telegram doesn't do direct DNS lookups. Telegram makes DoH requests which ISPs cannot intercept.” This also means ISPs cannot carry out their Man In The Middle attack and then lie to users that server cannot be reached.

- Ends