This document discusses big data security issues and encryption techniques. It begins with introducing the authors and providing an abstract about addressing security issues related to data integrity, confidentiality and availability. The main body then covers authentication, data, network and generic security challenges with big data as well as proposed solutions like encryption, logging and honeypot nodes. The document focuses on describing symmetric and asymmetric encryption algorithms including DES, AES, RSA and ECC. It compares the algorithms and concludes that encryption techniques can help secure big data stored in clouds, though current security levels may be improved.