Telegram offers a free premium subscription. But in return, it requires you to disclose your phone number to strangers

Telegram offers a new way to get a premium subscription for free. To do this, it is enough voluntarily to provide your phone number to transmit one-time passwords (OTP) to other users. While this may seem attractive at first glance, in reality, it is not the best idea - especially for a messaging service that is based on privacy.

In the Telegram terms of use, there is a section describing the new Peer-to-Peer Login (P2PL) program. Currently, it is only available on Android and in some (undefined) territories. By participating in the program, the user allows Telegram to use their phone number to send up to 150 text messages with OTP to other users who log into their accounts. Monthly, when the number is used to send the minimum amount of one-time passwords, the user receives a gift code for a monthly premium subscription.

What could go wrong ?

Source
• https://t.co/xgEtXj5qq5
• https://t.co/TkSI0VJcxB
Users in some countries are receiving this feature and the only good thing about it is that it's opt-in. #telegrampic.twitter.com/R1ptjGLJp7

— AssembleDebug (@AssembleDebug) March 24, 2024

This program has several privacy issues. Every time the number is used to send OTP, the recipient sees it. And if something unpleasant happens as a result, the Telegram terms are clear that it is the user's personal responsibility:

Accordingly, you understand and agree that Telegram is not responsible for any inconvenience, harassment, or damage caused by unwanted, unauthorized, or illegal actions taken by users who have learned your phone number through P2PL.

Furthermore, once the one-time password is sent from the user's number, the recipient can simply reply to it with a text message. People participating in the P2PL program are told not to send text messages to recipients of one-time passwords, even if they sent a message first. Telegram cannot prevent people from replying to the text of a one-time password and cannot influence this in any way.

Telegram says that it offers this program to make receiving access codes via SMS more secure in certain regions. Although it seems that the company is trying to avoid commission fees for sending codes via SMS - a move from the X (Twitter) playbook. At the same time, Telegram is not responsible if your operator charges you for sending access codes.

Overall, this seems like a very big risk to save $5 a month on premium subscriptions.

Source: The Verge