Telegram (software)

Telegram (software)
Name	Telegram
Developer	Pavel Durov
Released	2013
Operating system	Android (operating system), iOS, Windows (operating system), macOS, Linux
Genre	Instant messaging

Telegram (software) is a cloud-based instant messaging application developed by Pavel Durov and launched in 2013. It provides text messaging, voice and video calls, file sharing, and channel-based broadcasting across mobile and desktop platforms, positioning itself as an alternative to WhatsApp Messenger, Facebook Messenger, WeChat, and Signal (software). Built by a team originating from VK (service), Telegram emphasizes rapid message delivery, large group capacity, and cross-platform synchronization for users worldwide in contexts including Russia, United States, India, and European Union markets.

History

Telegram was founded by Pavel Durov and his brother Nikolai Durov after their tenure at VK (service), with development influenced by protocols such as XMPP and designs seen in ICQ and Skype. Early funding came from the Durov brothers and development launched in 2013 alongside rapid growth in regions affected by events like the Euromaidan protests and the 2014 Crimean crisis. Telegram expanded features through iterative releases, responding to competition from WhatsApp Messenger after its acquisition by Facebook, Inc. and policy changes at Twitter. Over time Telegram introduced channels, bots, and encryption features following examples from Signal (software) and critiques from privacy advocates associated with Edward Snowden revelations.

Features

Telegram offers one-to-one messaging, group chats, and public channels supporting millions of subscribers, mirroring functionalities in YouTube, Twitter, and Reddit communities for broadcasting. It supports multimedia sharing similar to Instagram (service), document exchange akin to Dropbox (service), and inline bots inspired by innovations from Telegram Bot Platform predecessors such as Skype Bots and Facebook Platform. Clients are available on Android (operating system), iOS, Windows (operating system), macOS, and Linux, with a Web version comparable to Gmail web interfaces. Features like stickers, animated emojis, voice messages, and video calls take cues from Snapchat, Viber, and LINE (software) ecosystems.

Security and privacy

Telegram implements server-client encryption for cloud chats and an optional end-to-end encryption mode called "Secret Chats," influenced by protocols evaluated in Open Whisper Systems work on Signal Protocol. Its cryptographic design references algorithms such as AES and RSA and includes forward secrecy and key exchange concepts used in Transport Layer Security. Debates over Telegram's custom protocol versus adoption of Signal Protocol or standards like OpenPGP have drawn comparisons to security audits performed for WhatsApp Messenger and Signal (software). Telegram's approach to metadata storage and law-enforcement access has been scrutinized alongside policies in European Union directives and rulings by courts such as the European Court of Human Rights.

Architecture and protocols

Telegram's architecture separates storage and messaging servers, employing a cloud-based model that distributes data across data centers in multiple jurisdictions, reflecting strategies used by Amazon Web Services, Google Cloud Platform, and Microsoft Azure. The client-server protocol is a custom protocol developed by the founders, with transport mechanisms adapting concepts from HTTP/2 and WebSocket for real-time delivery. For voice and video calls, Telegram uses peer-to-peer techniques and TURN/STUN-like traversal similar to implementations in WebRTC. The Bot API and platform integration allow third-party developers, echoing ecosystems created by Facebook Platform and Twitter API, while the app's file storage and CDN usage resemble designs used by Dropbox (service) and Cloudflare.

Reception and criticism

Telegram received acclaim from privacy advocates and technology media such as Wired (magazine), The Verge, TechCrunch, and BBC News for its speed, group capacity, and opposition to censorship seen in episodes involving Russia and Iran. Critics in outlets like The New York Times and The Guardian have questioned its security assumptions, user interface inconsistencies across Android (operating system) and iOS, and moderation policies compared to platforms such as Facebook, Inc. and Twitter. Academics studying online communities and extremism have noted Telegram's role in facilitating large-group coordination comparable to phenomena documented on Reddit and 4chan.

Legal issues and controversies

Telegram has been subject to regulatory actions, bans, and legal challenges in jurisdictions including Russia, Iran, China, Indonesia, and Brazil over content moderation, compliance with surveillance orders, and encryption refusal, echoing disputes faced by WhatsApp Messenger and Signal (software). Governments and law-enforcement agencies have issued takedown requests and court orders similar to cases involving Apple Inc. and Google LLC over lawful access. The platform has also been associated with the dissemination of extremist material and coordination of protests, prompting investigations by organizations such as Interpol and attention from legislative bodies in the European Union and United States Congress.

Category:Instant messaging clients Category:Cross-platform software