Cryptographic principles are the fundamental concepts and techniques that are used in the field of cryptography to secure communication and protect data. These principles include confidentiality, integrity, authentication, non-repudiation, and key management. Students will grasp how cryptography protects our digital world. We will start with its purpose — turning sensitive data into unreadable formats to keep it safe. Then, we will break down the key principles: confidentiality, integrity, and authentication. We will uncover the essential security services — like access control and non-repudiation. You will learn what they do and why they are crucial for any secure system. We will also explore the mechanisms that make it all work: encryption, hashing, and more.

This module introduces students to the foundational techniques of classical cryptography, focusing on how information is transformed to ensure secure communication. Learners will begin by understanding the basic concepts of plain text (readable data) and cipher text (encrypted data), establishing the groundwork for how cryptographic systems operate. The module then explores substitution techniques, where symbols in the plaintext are replaced with other symbols to obscure meaning. Examples such as the Caesar cipher, monoalphabetic cipher, and Vigenère cipher will be studied to illustrate how substitution alters data while maintaining structure. Next, students will examine transposition techniques, which rearrange the positions of characters without changing the symbols themselves. Methods like the Rail Fence cipher and Columnar transposition will demonstrate how order manipulation enhances security.

This module introduces symmetric key cryptography and its role in securing data. Learners will explore commonly used symmetric encryption algorithms such as AES, DES, 3DES, and Blowfish, and examine block cipher modes of operation including ECB, CBC, CFB, OFB, and CTR. The module also focuses on the practical application of encryption and decryption using different modes, along with an analysis of security vulnerabilities, key management challenges, and real-world use cases of symmetric cryptographic systems.

This module introduces symmetric key cryptography and the concept of shared secret keys. Learners will study classical encryption algorithms such as DES, Double DES, and Triple DES, and explore symmetric key encryption algorithms including IDEA, RC5, and modern standards such as AES and Blowfish. The module also compares block ciphers and stream ciphers through practical examples, and analyses the strengths, limitations, and real-world applications of symmetric encryption algorithms in secure systems.

Asymmetric Key Cryptography, also known as Public Key Cryptography, is a cryptographic system that uses a pair of mathematically related keys — a public key for encryption and a private key for decryption. This module explores the underlying mathematical concepts, key generation, encryption and decryption processes, digital signatures, and the role of asymmetric cryptography in securing modern communication systems such as SSL/TLS and email encryption.

The Asymmetric Key Cryptography Algorithms module focuses on the study and implementation of major public key algorithms used to secure data and communications. It covers key algorithms such as RSA, Diffie-Hellman, ElGamal, and Elliptic Curve Cryptography (ECC), exploring their mathematical foundations, key generation processes, encryption and decryption mechanisms, and real-world applications in digital security. The module also examines the strengths, weaknesses, and performance considerations of each algorithm in various cryptographic contexts.

The Public Key Infrastructure (PKI) module provides an in-depth understanding of the framework that enables secure electronic communication through the management of public-key encryption and digital certificates. This module explores the core components of PKI, including Certificate Authorities (CAs), Registration Authorities (RAs), digital certificates, certificate revocation, and trust models. It also discusses how PKI supports secure email, web authentication (SSL/TLS), code signing, and identity verification in modern networked environments.

This module introduces authentication and its role in securing digital systems. Learners will study password-based authentication methods and their limitations, and explore biometric techniques such as fingerprint, facial recognition, and iris-based authentication. The module also examines two-factor and multi-factor authentication, token-based approaches, single sign-on, certificate-based authentication, and Kerberos. Finally, learners will analyse the strengths, weaknesses, vulnerabilities, and real-world applications of different authentication techniques.

This module introduces the fundamentals of Internet security and cryptography. Learners will examine common Internet security protocols, including HTTPS, SSL/TLS, IPsec, SSH, SFTP, Kerberos, and OAuth 2.0/OpenID Connect. The module further explores advanced topics such as email security using PGP and S/MIME, core elements of web security, common web security threats, best practices, and emerging trends. Additionally, learners will study network security mechanisms including firewalls, intrusion detection and prevention systems (IDS/IPS), and virtual private networks (VPNs), and evaluate their role in securing modern Internet-based systems.

This module introduces modern cryptography and focuses on advanced cryptographic techniques designed to enable privacy, security, and trust in contemporary digital systems. Learners will explore secure multi-party computation, zero-knowledge proofs, fully homomorphic encryption, and oblivious RAM, along with functional encryption and private information retrieval. The module also examines symmetric searchable encryption and leakage-resilient cryptography, and concludes with applications of modern cryptography in secure voting and secure election systems.

End-Term Examination