This book constitutes revised and selected papers from the 5th International Symposium on Security and Privacy in Social Networks and Big Data, SocialSec 2019, held in Copenhagen, Denmark, in July 2019.

Web Scanner Detection Based on Behavioral Differences.- DMU-ABSE: Dynamic Multi-User Attribute-based Searchable Encryption With File Deletion And User Revocation.- A Novel Lattice-based Ciphertext-Policy Attribute-Based Proxy Re-Encryption for Cloud Sharing.- Blockchain-based Asymmetric Group Key Agreement Protocol for Mobile Ad Hoc Network.- Development of an Early Warning System for Network Intrusion Detection using Benford’s Law Features.- An RTP Extension for Reliable User-data Transmission over VoIP Traffic.- A Hybrid Covert Channel with Feedback over Mobile Networks.- Cloud-Aided Privacy Preserving User Authentication and Key Agreement Protocol for Internet of Things.- Integer Version of Ring-LWE and its Applications.- Correlate the Advanced Persistent Threat Alerts and Logs for Cyber Situation Comprehension.- A Secure Fine-Grained Micro-Video Subscribing System in Cloud Computing.- Exploit in smart devices: A case study.- Retrieve the Hidden Leaves in the Forest: Prevent Voting Spamming in Zhihu.- Online Event Detection in Social Media with Bursty Event Recognition.- Predicting Users' Emotional Intelligence with Social Networking Data.- Design and Implementation of Medical Dispute Governance Based on Blockchain.- Greedily Remove k links to hide important individuals in social network.- Man-in-the-Middle Attacks on Electrical Power Grid SCADA System.- Blockchain-based Threshold Electronic Voting System.- PassGrid: Towards Graph-Supplemented Textual Shoulder Surfing Resistant Authentication.- Learning from Imbalanced Data: A Comparative Study.