Sora Lee Jinwoo Kim Sangjun Ko Hyoungshick Kim A Security Analysis of Paid Subscription Video-on-Demand Services for Online Learning. 43-48 2016 ICSSA https://doi.ieeecomputersociety.org/10.1109/ICSSA.2016.15 conf/icssa/2016 db/conf/icssa/icssa2016.html#LeeKKK16