Jump to content

Telegram (software)

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Elehack (talk | contribs) at 14:38, 7 July 2015 (Try to clean up some grammar). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Telegram
Developer(s)Telegram Messenger LLP
Initial releaseAugust 2013 (2013-08)
Stable release
Android11.9.2[1] Edit this on Wikidata / 30 April 2025; 7 days ago (30 April 2025)
iOS, iPadOS11.10[2] Edit this on Wikidata / 30 April 2025; 7 days ago (30 April 2025)
Windows, macOS, Linux
(Telegram Desktop)		5.14.1[3] Edit this on Wikidata / 1 May 2025; 6 days ago (1 May 2025)
macOS11.9[4] Edit this on Wikidata / 1 May 2025; 6 days ago (1 May 2025)
Repository
Operating systemAndroid, Apple iOS, Windows Phone, MS Windows, Linux, OS X
Size9.6 MB (Android), 17 MB (Windows Phone)
Available inEnglish, Arabic, Spanish, German, Italian, Korean, Dutch, Portuguese (Brazil & Portugal), Russian
TypeInstant messaging
LicenseGPL v2 (client), closed source (server)
Websitetelegram.org

Telegram is an instant messaging system focusing on privacy and multi-platform availability. Telegram clients exist for both mobile (Android, iOS, Windows Phone) and desktop systems (Windows, OS X, Linux).[6][7] Telegram users can exchange messages encrypted end-to-end, self-destructing messages, along with photos, videos and files of any type up to 1.5GB in size.

Telegram is run by a German nonprofit organization backed by entrepreneur and philanthropist Pavel Durov. Its client code is open-source software, while its server-side code is currently proprietary. Software is also available from independent developers who make use of the Telegram API.

History

Telegram was launched in 2013 by brothers Nikolai and Pavel Durov, the founders of Russian VK, Russia's largest social network.[8] Telegram Messenger LLP is an independent nonprofit company based in Berlin, Germany,[9] which is not connected to VK.[10] Nikolai created the new MTProto protocol that the messenger is based on, while Pavel provided financial support and infrastructure through his Digital Fortress fund.[11]

In October 2013, Telegram had 100,000 daily active users.[8] On 24 March 2014, Telegram announced that it has reached 35 million monthly users and 15 million daily active users.[12] In December 2014, Telegram announced they had 50 million active users, generating 1 billion daily messages and that they had 1 million new users signing up on their service every week.[13]

Telegram runs contests challenging people to break their cryptography and disclose confidential information within a chat between two fake users. They claim that such challenges will be a permanent feature of their project. On December 21, 2013, a Russian IT-community user discovered a potential vulnerability in Telegram. They rewarded a $100,000 USD bounty after the problem was fixed.[14] On March 1, 2014 their first cryptography contest ended with no winners and they published the keys necessary to decrypt traffic.[15][16] Security researchers Moxie Marlinspike, the founder of Open Whisper Systems, and Taylor Hornby[self-published source] criticized Telegram's first cryptanalysis contest for being no proof of security and misleading the public.[17][18][19][20] Subsequently a new contest which allowed a Man-in-the-middle attack was started.[21]

As of February 17, 2015, Telegram's standard messages score 4 out of 7 points on the Electronic Frontier Foundation's secure messaging scorecard. It receives points for encryption during transit, having the code open to independent review, proper documentation of the security design, and for having had a recent code audit. It misses points because communications are not encrypted with a key the provider does not have access to, users can't verify contacts' identities, and because past messages are not secure if the encryption keys are stolen. In the same evaluation, Telegram's secret chat mode scored 7 out of 7 points.[22]

Features

Telegram accounts are tied to the phone number of the user, with possession of the phone with that number verified with a code sent by SMS or phone call to that phone. Subsequent logins are notified to the initial device with the IP address and time of login.[23] The phone number associated with an account can be changed without losing messages. While availing this migration, contacts of a user who have the previous phone number of the user, and are not blocked by the user, will receive the user's new number automatically.[23][24][25] Users can set up an alias or username which can be used by any other user to contact them, without having to add them to their contacts.[26] telegram.me is a webservice provided by Telegram which allows directly opening a chat with a user by following a hyperlink (like telegram.me/username) on supported devices.[24][25]

The application features two types of chats. Ordinary chats use client-server encryption and can be accessed from multiple devices. Secret Chats use end-to-end encryption and can only be accessed from the two participating devices.

User accounts are deleted automatically after 6 months of inactivity, and this can be changed to between 1 month and 1 year.

Users can control the 'last seen' timestamps, replacing them with fudged messages like "last seen within a week". They can block other users and silence chats.[27]

One or two checkmarks are displayed to indicate that the message is sent to the cloud or read by the recipient, respectively.[28] It is also possible to see the status of the recipient when responding to a message.[8]

Their latest release saw the introduction of new features such as replies, mentions, link previews and session management.

Standard messages

With standard messages Telegram supports cloud messaging and file sharing (with multimedia and documents up to 1.5 gigabyte in size) with synchronization across devices.[6][29] The message history can be searched without opening or downloading the conversations.[30] Sharing audio notes, geo-zones, GIFs or animated memes via Giphy[30] are also supported.

Private lists can be made for broadcasting the same message to multiple contacts.[29] Group messaging is possible with up to 200 members in a group, and an unlimited number of groups.[31]

Secret chats

A "secret chat" confirmation notice. Screenshot in Spanish from Apple iOS 8.

Telegram claims it is more secure than some other messengers such as WhatsApp and LINE. Conversations are encrypted with AES-256 using the MTProto protocol developed by Telegram.[8][32][33] Only two devices may use the secret chat simultaneously.[26]

While using secret chats in official clients, messages deleted on one device are deleted on the other device too, a special message is displayed when a screenshot is taken, and messages can be set to be deleted automatically (self-destruct) at pre-set time intervals.[34]

On December 1, 2014, Telegram implemented Perfect Forward Secrecy in Secret Chats. This enables periodically changing the encryption keys utilized, keeping past communications safe. Official Telegram clients initiate re-keying once a key has been used to decrypt and encrypt more than 100 messages, or has been in use for more than one week, provided the key has been used to encrypt at least one message. Old keys are then discarded and cannot be reconstructed, even with access to the new keys currently in use.[24][25][35]

Architecture

Protocol

Explanation of secret chats, included in Telegram, using the keys of the devices, then share the code modified for use as single key encryption and locally synchronized.

The new MTProto protocol created by Nikolai Durov is based on 256-bit symmetric AES encryption, RSA 2048 encryption and Diffie–Hellman key exchange.[36]

Licensing

All official Telegram clients (and some of the unofficial clients) are open source.[37] Telegram's server-side software, however, is proprietary. Pavel Durov said the server code is not free software because it would require major architecture redesign to allow independent servers to act as a unified Telegram cloud.[38]

List of applications

File:Webogram Screenshot.png
Telegram Web, aka Webogram.

Telegram has various clients with support for more platforms expected in the future. Its server system is decentralized and distributed around the world to improve response times by geographical position.[39] This list includes versions developed on official platforms backed by the development team, or supported by the community to be integrated in the future.

Desktop

Telegram Desktop running on Arch Linux.
  • Telegram for OS X. The first official application, available for OS X.
  • Telegram Desktop: Official multi-platform desktop app. It can be used in Microsoft Windows (portable application), OS X and GNU/Linux.
  • Cutegram: Unofficial multi-plattform desktop app based on Qt with Secure Chat support.[40]

Mobile

Others

Security concerns

The majority of cryptographic experts [who?] doubt the security of Telegram's self-developed protocol MTProto. Especially the immediate hashing of the secret message with the already broken SHA-1 represents a single point of failure in the implementation.[47][48][49] The server is able to perform a man in the middle attack, because there is no authentication of the messages. So, it is possible for the server provider to forge messages in the name of the user. Further, the keys are not generated randomly, as it is common throughout cryptography, but are calculated from the plain text message. This is seen as a gross error in the conception of the protocol.[50] All messages are stored unencrypted on the device and can be accessed easily by an attacker with access to the device.[51]

See also

References

  1. ^ "Telegram". Google Play. Retrieved May 3, 2025.
  2. ^ "Telegram Messenger". App Store. Retrieved May 1, 2025.
  3. ^ "Release 5.14.1". May 1, 2025. Retrieved May 1, 2025.
  4. ^ "Telegram for macOS". Retrieved May 1, 2025.
  5. ^ "Telegram.org Site Info". Alexa, Inc. Retrieved May 5, 2015.
  6. ^ a b "List of Telegram applications". February 6, 2014.
  7. ^ "Che cosa è Telegram, Squer.it" (in Italian).
  8. ^ a b c d "Meet Telegram, A Secure Messaging App From The Founders Of VK, Russia's Largest Social Network". TechCrunch. October 27, 2013.
  9. ^ "Surveillance drives South Koreans to encrypted messaging apps". The Verge. October 7, 2014.
  10. ^ https://telegram.org/faq#q-who-are-the-people-behind-telegram
  11. ^ "Russia's Zuckerberg launches Telegram, a new instant messenger service". Reuters. August 30, 2013.
  12. ^ Telegram Hits 35M Monthly Users, 15M Daily With 8B Messages Received Over 30 Days, TechCrunch, March 24, 2014
  13. ^ Telegram Reaches 1 Billion Daily Messages, Telegram, December 8, 2014
  14. ^ "Crowdsourcing a More Secure Future". Telegram blog. December 21, 2013. Retrieved March 3, 2014.
  15. ^ "Winter Contest Ends". Telegram blog. March 2, 2014. Retrieved March 3, 2014.
  16. ^ Robin Wauters (December 19, 2013). "Cracking contest: first one who breaks Telegram gets $200,000 in bitcoins (but really, nobody wins)". Tech.eu. Retrieved December 4, 2014.
  17. ^ Marlinspike, Moxie (December 19, 2013). "A Crypto Challenge For The Telegram Developers". Thought crime. Retrieved March 2, 2014.
  18. ^ Hornby, Taylor (December 19, 2013). "Telegram's Cryptanalysis Contest". Crypto Fails. Retrieved March 2, 2014.[self-published source]
  19. ^ Wauters, Robin (December 19, 2013). "Cracking contest: first one who breaks Telegram gets $200,000 in bitcoins (but really, nobody wins)". EU: Tech. Retrieved March 2, 2014.
  20. ^ Alkemade, Thijs (April 2, 2014). "Breaking Half of the Telegram Contest" (World wide Web log). DE. Retrieved April 2, 2014.[self-published source]
  21. ^ "$300,000 for Cracking Telegram Encryption".
  22. ^ "Secure Messaging Scorecard. Which apps and tools actually keep your messages safe?". Electronic Frontier Foundation. February 27, 2015.
  23. ^ a b Lopez, Miguel, Configurando Telegram en el iPhone, en la web y en el Mac (in Spanish), Applesfera, retrieved December 4, 2014 {{citation}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  24. ^ a b c Munizaga, Jonathan (December 1, 2014). "Telegram ya permite migrar conversaciones y contactos a una línea nueva" (in Spanish). Wayerless. Retrieved December 2, 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  25. ^ a b c Mateo, David G (December 1, 2014). "Telegram ahora permite traspasar mensajes al cambiar de número" (in Spanish). TuExperto. Retrieved December 2, 2014.
  26. ^ a b "Secure Messaging App Telegram Adds Usernames And Snapchat-Like Hold-To-View For Media". Techcrunch. October 23, 2014. Retrieved October 23, 2014.
  27. ^ "Basics". FAQ. Telegram. Retrieved February 13, 2014.
  28. ^ "What do the green ticks mean?", FAQ, Telegram, February 23, 2014
  29. ^ a b "Telegram: una alternativa gratuita a WhatsApp con ventajas y algún punto oscuro" (in Spanish). March 1, 2014. Retrieved December 4, 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  30. ^ a b "Telegram para iOS, Android se actualiza con soporte de GIFs" (in Spanish). Cnet. Retrieved December 12, 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  31. ^ "Should WhatsApp be wary of Telegram?". February 13, 2014.
  32. ^ "How secure is Telegram?", FAQ, Telegram
  33. ^ Description of MTProto Mobile Protocol, Telegram
  34. ^ "Telegram FAQ". n.d. Retrieved February 10, 2014.
  35. ^ Perfect Forward Secrecy, Telegram, December 14, 2014
  36. ^ "Telegram technical FAQ for Advanced users".
  37. ^ "Source code", Telegram (links), retrieved February 12, 2013
  38. ^ "Pavel Durov: "No application is 100% safe"". Turing. ES: El Diario. February 2, 2014. Retrieved February 12, 2014.
  39. ^ "Telegram, el chat que compite con Whatsapp". El País (in Spanish). UY. Retrieved February 13, 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  40. ^ http://aseman.co/en/products/cutegram/
  41. ^ "Telegram se actualiza para la pantalla del iPad" (in Spanish). Cnet. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  42. ^ "Telegram-Anleitung: So benutzt man den Messenger" (in German). Newsslash.
  43. ^ "Telegram se actualiza con compatibilidad para Android Wear" (in Spanish). Sevilla: ABC. Retrieved December 7, 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  44. ^ "Telegram Beta disponible para Windows Phone" (in Spanish). Wayerless. May 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  45. ^ a b "Apps". Telegram (in Spanish). Retrieved February 21, 2014.
  46. ^ "Ngram se convierte en el cliente oficial de Telegram para Windows Phone" (in Spanish). Retrieved May 23, 2014. {{cite web}}: Unknown parameter |trans_title= ignored (|trans-title= suggested) (help)
  47. ^ Geoffroy Couprie (December 17, 2013), Telegram, AKA “Stand back, we have Math PhDs!”, Unhandled expression, retrieved March 24, 2014 {{citation}}: Cite has empty unknown parameter: |offline= (help)
  48. ^ Hacker News: Telegram – secure, free messaging
  49. ^ Telegram's Cryptanalysis Contest, Crypto Fails, December 19, 2013, retrieved March 24, 2014 {{citation}}: Cite has empty unknown parameter: |offline= (help)
  50. ^ Konstantin Kovshenin, Telegram, AKA “Stand back, we have Math PhDs!”, Unhandled Expression, retrieved June 15, 2015
  51. ^ Zuk Avraham, Telegram App Store Secret-Chat Messages in Plain-Text Database, Zimperium Mobile Security, retrieved June 15, 2015
Wikimedia Commons has media related to Telegram Messenger.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Telegram_(software)&oldid=670365765"