Photo: Álvaro Ibáñez/FlickrAFP · 13 Sep 2016, 12:37Published: 13 Sep 2016 12:37 GMT+02:00Smartphone app Telegram, favoured by the Islamic State group thanks to the encrypted messaging it offers, is proving a headache for French anti-terror investigators. After Isis gunmen and suicide bombers massacred 130 people in Paris in November, Telegram blocked dozens of public channels that were being used to spread extremist messages. $300,000 code-cracking challengeSo confident is Telegram in its encryption, it has offered up to $300,000 to anyone who manages to crack its system. Moreover, the app has a feature that allows users to set messages to auto-destruct, making it impossible to recover them later for use in investigations. French intelligence chief Patrick Calvar described the app in May as "the main network used by terrorists".

Source: The Local September 13, 2016 11:15 UTC