Ravishankar works as a Senior Researcher in Security in the Telecommunications Department at Technical University Berlin. His research themes are related to mobile telecommunication and involved security threats. This ranges from GSM/UMTS/LTE network security to end-user device security. Previously, he was involved in the investigation of weaknesses in the femtocell security architecture at TU Berlin. Further, he discovered USSD code vulnerabilities in Android devices. Ravishankar's research has previously been presented at the Black Hat, Hack In The Box, Ruxcon, Troopers, T2, and HES.