Telegram is a cloud-based mobile and desktop messaging appinstant messaging service for mobiles and desktops (messages, phone calls, video calls, team communication). Telegram app works on Android, iOS, Mac, Linux and windows operating systems.
- API interface Terms of Service https://core.telegram.org/api/terms-of-use
- The actual Terms of Service are very limited (chekcked undated version): https://telegram.org/privacyAPI interface TOStos.
- Privacy (Aug 14th 2018 updated as May 25th 2019 checked): https://core.telegram.org/api/terms-of-useprivacy
Evaluation (03 Feb 2017 (13 Oct 2020)
- End to End ecryption is possible (Secret Chat)
- The Self-Destruct Timer is available for all messages in Secret Chats or any messages you sent or received can be deleted in any one-on-one conversation, messages are deleted from both participants (but not in Group Chat)
- Versatile; Group discussions,Bots, Channels, Multimedia, File Transfer up to 1,5Gt2 GB
- Open (mainly) Source (at least APIs)
- Auditing possilbe for Third Party
- Good documentation (esp. for Security Features)
- Compatible with other messaging apps, for example Slack and Irc
- Account can be removed by user (all data will be removed)
- Unused account will be deleted after 6 months afer after last login, all data will be removed
- Two-step authentication possible
- No advertisements
- Data is stored to Cloud (for EU/ETA users the service is in the Netherlands
- Phone app is mandatory to install (Utilises mobile phone contacts although desktop or browser used)
- Encryption is not on by default
- Uses own encryption protocol MTProto Mobile Protocol https://core.telegram.org/mtproto/description (which is well descripted ) but only some of Telegam´s clients uses it
- Terms of Service inadequate
- Logging is done by full (international) phone number and password while installing Telegam Client. Account is verified by SMS.
- Two-step authentication can be switched on in settings (password + SMS)
- No Inadequate TOS, thus no full support and guarantee for availability
- Telegram Org (Pavel and Nikolai Durov).
- Pavel Durov is financing Telegram for ideological reasons.
- Signal, WhatsApp