Cyber security attacks are growing exponentially. Security specialists must occupy in the lab, concocting new schemes to preserve the resources and to control any new attacks. Therefore, there are various emerging algorithms and techniques viz. DES, AES, IDEA, WAKE, CAST5, Serpent Algorithm, Chaos-Based Cryptography McEliece, Niederreiter, NTRU, Goldreich–Goldwasser–Halevi, Identity Based Encryption, and Attribute Based Encryption. There are numerous applications of security algorithms like cyber security, web security, e-commerce, database security, smart card technology, mobile security, cloud security, digital signature, etc. The book offers comprehensive coverage of the most essential topics, including: This book serves as a textbook/reference book for UG, PG, PhD students, Teachers, Researchers and Engineers in the disciplines of Information Technology, Computer Science and Engineering, and Electronics and Communication Engineering.