The Telegram Way
Back in 2013, when we were launching Telegram, we carefully considered both approaches. We knew we didn’t want to violate our users’ privacy by shifting the responsibility for their data to third-party backups like WhatsApp or Viber do. Neither did we want to deprive our users of functionality that they enjoyed in other apps and doom Telegram to join the ranks of niche apps.
So after some research we decided to introduce 2 kinds of chats – Secret chats and Cloud chats.
Secret chats are e2e-encrypted chats that never under any circumstances get backed up. Cloud chats are encrypted in the same way, but also have a built-in cloud backup. Cloud chats are designed for the majority of users – the majority that in another app like WhatsApp would rely on less secure third-party backup storage. Unlike what you have in niche apps, the traffic between cloud chat users and secret chat users on Telegram is mixed (the encryption is the same in both cases, but in cloud chats our servers do have access to the encryption key), so individuals can not be singled out and targeted based on the fact that they use secret chats and thus have something to hide.
4 Reasons Why The Telegram Way Makes More Sense
There are four main reasons why we decided to use two types of chats as opposed to having one type of chats like older apps such as WhatsApp:
1) Unlike WhatsApp, we don’t give out our users’ data to third parties via backups. Instead, we rely on our own distributed cross-jurisdictional encrypted cloud storage which we believe is much more protected than what megacorporations like Google and Apple can offer. To give you an idea about this difference: while Telegram has disclosed no private data to third-parties from its cloud so far, this year alone Apple satisfied 80% of data requests from the Chinese (!) government (and is even building a data-center for private iCloud data in China).
2) Unlike WhatsApp, we can allow our users to access their Telegram message history from several devices at once thanks to our built-in instant cloud sync. Thus we can provide easy and consistent UX on macs, PCs, iPads and even linux servers.
3) Unlike on WhatsApp, on Telegram you don’t have to store your entire message history on your phone all the time – you can always download older messages and media on demand when you need them. This saves a lot of disk space and memory, which is particularly important for our users in the developing markets. On Telegram, shortage of local storage never leads to data loss.
4) Unlike WhatsApp, Telegram is able to provide its users with advanced functionality, such as persistent group chats with up to 10,000 members or channels with no limit on max size. These technologies can not be implemented within the “e2ee+third-party backups” paradigm. Our roadmap is filled with features that are impossible to build on a obsolete architecture like WhatsApp's that has to rely on third-party backups instead of relying on its own built-in cloud accessible in real-time.
These are the reasons why we, ultimately, decided to go with the “two kinds of chats” approach, which is more secure (Telegram cloud is better protected than Apple/Google storage), more transparent (you can actually see which of your e2e-encrypted messages go to the cloud and which don’t) and more feature-rich (we can implement features that I mentioned above and many more in the future). We believe our “two kinds of chats” approach makes more sense in the long run, which is why it has since been copied by Kakao (2014), Line (2015), and last year by Google Allo and Facebook Messenger. These companies did their own research that proved that the Telegram way is more scalable, secure and transparent.
Source:
https://telegra.ph/Why-Is...ncrypted-by-Default-08-14