Cryptography

Birla Institute Of Technology And Science–Pilani (BITS–Pilani) via Coursera

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Details

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Provider

Coursera
Pricing

Paid Course
Languages

English
Certificate

Paid Certificate Available
Duration & workload

3 days 1 hour 27 minutes
Sessions

On-Demand
Level

Intermediate
Subtitles

English

Found in

Overview

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This course is designed to give you a solid foundation in how information is protected in the digital age. Step into the world of cryptography—the science behind secure communication. This course aims to prepare you for an exciting and in-depth journey into the world of modern cryptography. Designed for undergraduate students, it introduces the core principles, mathematical foundations, and practical applications that make secure digital communication possible today. You will start by learning the basics of cryptographic systems, including classical ciphers (block and stream), modular arithmetic, and finite fields—tools that form the backbone of encryption. As the course progresses, you will explore key mathematical ideas like discrete logarithms and primality testing, which support widely used algorithms such as RSA and digital signatures. You will then dive into modern cryptographic techniques, including symmetric encryption (DES, AES), public-key cryptography, hash functions, authentication methods, and key management strategies. You will also be introduced to advanced topics like linear and differential cryptanalysis, perfect secrecy, and cryptographic protocols that ensure secure communication. A special focus will be placed on theoretical tools such as interactive proofs, zero-knowledge proofs, probabilistic algorithms, and pseudo-randomness—concepts that help build secure systems even in hostile environments. To connect theory with practice, the course includes real-world applications like email and web security, digital rights management, firewalls, and protection against malware. By the end of the course, you will have a solid understanding of both the theory and practice of cryptography, preparing you for further studies in cybersecurity or careers in secure software development and information security. This course will emphasise on principles and practice of cryptography and network security: classical systems, symmetric block ciphers (DES, AES, other contemporary symmetric ciphers), linear and differential cryptanalysis, perfect secrecy, public-key cryptography algorithms for factoring and discrete logarithms, cryptographic protocols, hash functions, authentication, key management, key exchange, signature schemes, email and web security, viruses, firewalls, digital right management, and other topics.

Syllabus

Course Introduction

In this module, the learners will be introduced to the course and its syllabus, setting the foundation for their learning journey. The course's introductory video will provide them with insights into the valuable skills and knowledge they can expect to gain throughout the duration of this course. Additionally, the syllabus reading will comprehensively outline essential course components, including course values, assessment criteria, grading system, schedule, details of live sessions, and a recommended reading list that will enhance the learner’s understanding of the course concepts. Moreover, this module offers the learners the opportunity to connect with fellow learners as they participate in a discussion prompt designed to facilitate introductions and exchanges within the course community.

Conceptual Foundations of Information Security

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.

Fundamentals of Cryptographic

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.

Symmetric Key Cryptography

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.

Symmetric Key Encryption Algorithms

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

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.

Asymmetric Key Cryptography Algorithms

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.

Public Key Infrastructure (PKI)

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.

User Authentication Techniques

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.

Internet Security and Cryptography

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.

Modern Cryptography

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.