Cryptographers unearth vulnerabilities in Telegram's encryption protocol
https://www.cyberscoop.com/telegram-app-security-encryption/
https://archive.ph/SK6o1
The most significant of the vulnerabilities the researchers uncovered is what they called the “crime-pizza” vulnerability.
https://web.archive.org/web/20200717215711/https://twitter.com/realAlexBaumann/status/1284240420302536705