Abstract

The base of this chapter rests on the basics of fundamental concepts and modern cryptography techniques and their use in secure communication systems. Moreover, apart from their role in ensuring data confidentiality, integrity, authenticity, and non-repudiation, some key cryptographic algorithms discussed include hashing, digital signature, symmetric encryption, and asymmetric encryption. It also points out the real use of the technology that has gained much momentum with blockchain technology, e-commerce, and encrypted communications, besides new developments in post-quantum security and quantum cryptography. It also considers the challenges of deploying cryptographic solutions within a high-stakes, dynamic environment and discusses how defenses can be hardened against evolving threats.