The growing need for computing on bigdata is getting higher, the three basic dimensions of big data are (referred as "3V" challenges) high volume, variety and velocity. The other upcoming challenge in the area of bigdata is Veracity, which means the trustworthiness of the data that is how secure the data is received, stored, processed and transmitted. Hence this Veracity is becoming a new dimension in the bigdata era. In this paper, we present a survey on various techniques that impose security and privacy over the bigdata. We elaborate on the techniques like cryptographic algorithms, Privacy- Preserving Cosine Similarity Computing protocol (PCSC), Optimized Balanced Scheduling (OBS), a trapdoor function and mention the differences in terms of performance based on cost and time.

Keywords-big data, privacy, security, PCSC, OBS