Certificates shipped for course completion till 25th of the last month.

Select Your Style

Choose your layout

Color scheme

Cryptography and Network Security

Cryptography and Network Security

Cryptography and Network Security

About the course

Professor Debdeep Mukhopadhyay, a faculty from the department of Computer Science and Engineering at the Indian Institute of Technology, Kharagpur has designed this course on Cryptography and Network Security covering all the fundamental concepts of Cryptography and Network Security. The term Cryptography which translates as "secret writing," refers to the science of concealing the meaning of data, so that only specified parties understand a transmission's contents. Cryptography has existed for thousands of years; for most of history, however, the users of cryptography were associated with a government or organized group and were working to conceal secret messages from enemies. These days, millions upon millions of secure, encoded transmissions happen online each day and cryptographic standards are used to protect banking data, health information, and much more. Without cryptography, e-commerce as we know it would be impossible. Since online security threats evolve so quickly, there are dozens of different schools of thought on how best to use encryption to enhance network security not just for governments, but for businesses and end users, too. This course comprises of video lectures which can be viewed online and offline as per the convenience of the user. It also has questions/assignments for hands on practice. So, this makes it all together a complete package.


In this course, the user will learn about the underlying principles of cryptography and network security. In addition to this, it develops the mathematical tools required to understand the topic of cryptography. Beginning from the classical ciphers to modern day ciphers, the course extensively covers the techniques and methods required for the proper functioning of the ciphers. The course also covers the construction and cryptanalysis of block ciphers, stream ciphers and hash functions. This course also defines one way functions and trap-door functions and presents the construction and cryptanalysis of public key ciphers, namely RSA. The key exchange problem and solutions using the Diffie-Hellman algorithm are discussed. Message Authentication Codes (MAC) and signature schemes are also detailed. The course covers the modern trends in asymmetric key cryptography, namely using Elliptic Curves. The course concludes with the design rationale of network protocols for key exchange and attacks on such protocols.


Advantages of learning this course
Target Audience
Why learn Principles of Human Resource Management?
Course Features
Test & Evaluation
  • Timeline
  • Scholarship Details

Please Login or Register to fill the Scholarship form.

Scholarship Application

Under Graduate

Post Graduate



Other Information



  1. Introduction

    1. Why do we need to study cryptography?

    2. What is the communication game?

    3. What is the protocols concept and what are the properties of function f(x)-1 and f(x-2)?

    4. What is the assumed protocol?

    5. What are the problem arising with the new concept?

    6. What is coin flipping over telephone?

    7. Can we look at security analysis and an example?

    8. How can we get the function f(x)?

    9. How can we calculate the success probability?

    10. What is planning strategy?

    11. What is the probability of cheating case 1 and 2?

    12. How can we calculate success probability experimentally?

    13. What is the magic function?

  2. Overview on Modern Cryptography

    1. What are the the three goals of modern cryptography?

    2. What are confidentiality, integrity, availability and mechanism?

    3. What are cryptographic attacks?

    4. What is the objective of crypt analysis?

    5. What is the non cryptanalytic attack and confidentiality threat?

    6. What are the threat to integrity 1, 2 and 3 and threat of availability?

    7. What are active and passive attacks?

    8. What are security services?

    9. What is security mechanism?

    10. What is digital signature and authencation and more on security mechanism?

    11. What is the relation ship between service and mechanism?

    12. What are cryptographic algorithms and what are steganography / modern techniques?

  3. Introduction to Number Theory

    1. What are congruences and their properties?

    2. What is equivalence and residue class of modulo m and examples of class 1 class and 2?

    3. What is theorem on equilance and residue?

    4. Can we look at an example on the given theorem?

    5. What is field theory (semigroups) and field theory (implication)?

    6. What is monoid and example on neutral elements?

    7. What are residue class ring and unit group?

    8. What are zero divisors?

    9. What is Fermat's Little Theorem?

  4. Probability and Information Theory

    1. What is the importance of Probability and cipher uncertainity?

    2. What is Semantic Security and the notions of security and computational security?

    3. What are probability definitions (statistical and classical)?

    4. What is probability distribution of random variables and what is Uniform and Binomial distribution?

    5. Law of large numbers 1?

    6. What is the law of large numbers 2?

    7. What is the Birthday paradox problem, actual problem and computing problem 1 and 2?

    8. What is an application of the paradox problem?

    9. What is Floyd's cycle finding algorithm?

    10. How can we measure information and entropy?

  5. Classical Cryptosystems

    1. Definitions behind cypher designs 1 and 2?

    2. What is Kerchoffs Principle and what is Cryptographic Communication?

    3. What is Classical Cryptography and simple substitution?

    4. What are the properties required for encryption and what is substitution cypher?

    5. What is the affine cypher and its inverse?

    6. What is generalized affine cipher and an example of it?

    7. What are some Important Results 1 and 2?

    8. What are monoalphabetic, polyalphabetic and vigenere ciphers?

    9. What are hill ciphers and permutation ciphers?

  6. Cryptanalysis of Classical Ciphers

    1. What is Kerckhoff's principle and the models of cryptanalysis 1 and 2?

    2. What is statistical analysis?

    3. What is cryptanalysis of a monoalphabetic, affine and vigenere cipher?

    4. What is Kasiski test?

    5. What is index of coincidence 1?

    6. What is index of coincidence 2?

    7. What are mutual index of coincidence?

    8. What is computing mutual index?

    9. Can we look at two examples of vignere cipher?

    10. What is cryptoanalysis of hill cipher?

  7. Shannons Theory

    1. What is Shannons theory and unconditional security?

    2. What are aprior and aposteriori probabilities?

    3. What is perfect secrecy 1 and 2?

    4. What is an example on perfect secrecy 1 and 2 and generalisation of example?

    5. Can we look at example on shift cipher with perfect secrecy and its mathemetical formulation?

    6. What is the theorem on perfect secrecy?

    7. What are cryptographic properties 1 and 2?

  8. Shannons Theory (Contd...1)

    1. What is one time pad, uncoditionally secured scheme and practical problems?

    2. Can we revisit entropy?

    3. What is Huffman encoding with example?

    4. Can we look at more results on entropy?

    5. What is the proof of the theorem 1 and 2?

    6. Can we compare perfect cipher with ideal cipher?

    7. What is unicity, brute force attack, spurious keys, entropy of plain text and redundance?

  9. Shannons Theory (Contd...2)

    1. What is protection against brute force?

    2. What are spurious keys, second order approximation and redundancy?

    3. What is the lower bound of equivocation of key?

    4. What are possible keys?

    5. What is the lower bound of spurious key?

    6. What is unicity distance and unicity distance for substitution ciphers?

    7. Can we look at example on endomorphic cipher?

    8. What is the proof of commutative ciphers?

    9. What are idempotent ciphers and what are the conclusions drawn?

    10. What is the concept of rounds?

  10. Symmetric Key Ciphers

    1. What is symmetric key setting and types of symmetric key ciphers?

    2. What are full size key ciphers?

    3. What are permutation ciphers and partial-size key ciphers 1 and 2?

    4. What are the components of modern block ciphers?

    5. What are diffusion (P) boxes, S box and other components?

    6. What are the properties of EXOR?

    7. What is diffusion and confusion data flow diagram?

    8. What are practical ciphers (feistel cipher)?

    9. What is Feistel permutation?

  11. Block Cipher Standards (DES)

    1. What are data encryption standards and DES numerology?

    2. What are initial permutations and DES expansion table?

    3. What is S box table with decimal values and what are the properties of S box?

    4. What is DES subkey?

    5. Some important points about DES and an exercise?

    6. What are weak keys?

    7. What is sample round key generation and multiple DES?

    8. What is meet in the middle attack and security of 2DES?

  12. Block Cipher Standards (AES)

    1. What are finite fields and complex fields?

    2. What is polynomial over a field?

    3. What are the operations on a polynomial?

    4. Can we look at an addition example?

    5. What is multiplication operation, irreducible polynomial and an example of multuplication?

    6. What is the concept of a generator( Fernets Little theorem)?

    7. What is the proof of the theorem?

    8. What is AES and Rijndael algorithm?

    9. What is the difference between Rijndael and AES?

    10. What is the the AES Sbox and AES Sbox Affien mapping?

    11. What are mix columns?

  13. Block Cipher Standards (AES) (Contd.)

    1. What is the AES key scheduling?

    2. What is key expansion?

    3. What is the key scheduling algorithm?

    4. What is the round constant?

    5. when nk>6 and an example on different key sizes?

    6. What is the algorithm of encryption process?

    7. What is inverse cipher (decription)?

    8. What is the algorithm of decryption process?

    9. How can we push a linear transformation using a XOR, steps for a two round variant and implementation on modern processors?

    10. How can we make AES computation fast, some furthur reading and an exercise?

    11. What happens when the number fo rounds of cipher are fixed?

  14. Linear Cryptanalysis

    1. What is cipher transformation?

    2. What is the definition and algorithm of SPN ciphers?

    3. Can we look at an example of Gpig cipher and modification of SPN structure and key scheduling of the cipher?

    4. What is linear cryptanalysis ?

    5. What is piling up Lemma and generalised Lemma?

    6. What is the linear approximation of S box and S box in terms of random variables?

    7. What is representing the approximations?

    8. What is linear approxiamtion table?

    9. What is linear attack explanation 1 and 2 and what is the attack?

  15. Differential Cryptanalysis

    1. What are the key points of Differential Cryptanalysis?

    2. Can we have a recap of Gpig example?

    3. What is the informal working of the attack and obtaining differential characteristics fo the S box?

    4. What is the delta set and an example set?

    5. What is a non uniform output distribution of XOR's of a S box and difference distribution table and propagation ratio?

    6. What is differential trail?

    7. Can we look at an example of differential trail?

    8. How can we obtain differential for 3 rounds and a real attack?

    9. How can we have an immunty against DC, an exercise and furthur reading?

  16. Few other Cryptanalytic Techniques

    1. What are common cryptanalytic techniques and a cap of differential cryptanalysis?

    2. What is Boomerang attack?

    3. Can we look at an example of Boomerang attack?

    4. What is the M layer?

    5. Can we look at differential analysis of Phi function 1?

    6. Can we look at differential analysis of Phi function 2?

    7. How can we obtain full round characteristics and the actual attack?

    8. How can we find k1 key and other keys?

    9. What is the square attack on 4 round AES and the invariance of the active attack?

  17. Overview on S-Box Design Principles

    1. What is S Box?

    2. What is boolean function?

    3. Can we look at explanation to boolean functions and scalar product of sequences?

    4. What is non linearity 1 and 2?

    5. Can we look at compact representation of linear functions?

    6. What is the effect of input transformation and a strict avalanche criteria?

    7. a strict avalanche criteria?

    8. What is boolean function satisfying SAC?

    9. Can we look at an example of a boolean function satisfying SAC?

    10. What is Bent function and its example?

    11. How can we create a balanced non linear function?

  18. Modes of Operation of Block Ciphers

    1. What is the need for modes of block ciphers and what is electronic code book?

    2. What are the properties of modes?

    3. How can the ciphertext be stolen 1?

    4. How can the ciphertext be stolen 2?

    5. What is cipher block chaining?

    6. What are IV based attacks?

    7. What is error propabation in case of CBC, its disadvantages and certain points?

    8. What is output feedback mode and counter mode

    9. How do modern day modes function and what are tweakable modes

    10. What is watermark attack

  19. Stream Ciphers

    1. Can we compare block with stream ciphers and what is one time pad

    2. What are synchronous stream ciphers?

    3. What are the properties of synchronous stream ciphers and its model?

    4. What are self synchronisation stream ciphers and their properties

    5. What is feedback shift register and linear feedback shift register?

    6. Can we look at an example of LFSR and periodicity of its sequences

    7. How can we reconstruct the LFSR (an example)?

  20. Stream Ciphers (Contd...1)

    1. Some basic concepts related to Stream Ciphers and what is the LFSR structure

    2. How can we generate a sequence and theorem of LFSR

    3. What is the proof for the theorem 1 and 2

    4. What is linear complexity and considering another lemma

    5. What is Berlekamp Masseys algorithm?

    6. What is discrepancy and how can it be corrected?

    7. How can we prove the induction hypothesis

    8. What is recursive construction of polynomial

    9. Can we look at an example

  21. Stream Ciphers (Contd...2)

    1. What are non linear feedback shift registers

    2. What is de bruijn sequence and an example of de Bruijn generator

    3. How can we convert LFSR to a de Brujin FSR and what are stream ciphers based on LFSR?

    4. What is non linear combination generator and an example using Geffe generator

    5. What are correlation attacks

    6. What is correlation immunity

    7. What is summation generator, clock controlled generator and shrinking generator and what are modern stream ciphers

  22. Pseudorandomness

    1. What is the usefulness of Pseudorandomnessin cryptography and what is random bit generator?

    2. What is a pseudorandom bit generator and random tests

    3. What is polynomial statistical test and next bit test and the universality of the next bit test

    4. What is random bit test and de-skewing

    5. What is FIPS pseudo random bit generator

    6. What are the five basic tests

    7. What is normal distribution and chi square distribution

    8. What is hypothesis testing

    9. What is he RSA bit PRBG and Blum Blum Shub Generator

  23. Cryptographic Hash Functions

    1. What is data integrity, applications of hash function and what is a keyed hash function

    2. What is a definition of cryptographci hash function and how do we define a preimage problem

    3. What is collision problem and the random oracle model

    4. What is an example of non ideal hash function

    5. What is independence theorem and what is algorithm in the random oracle model

    6. What is the algorithm of find-preimage and find second preimage

    7. What is algorithm find collision and comparison of security criteria

    8. What is the first reduction

    9. What is the second reduction

  24. Cryptographic Hash Functions (Contd...1)

    1. What are the proof on the assumption 1

    2. What is the proof on the assumption 2

    3. Can we look at the construction of iterated hash function

    4. What is optimal output construction and a typical preprocessing step

    5. What is merkel damgard construction

    6. What is the algorithm

    7. What is the proof of collision resistance

    8. What is the proof of collision resistance (assuming different cases)

    9. Can we conclude considering t=1 case

    10. What are the different theorems applicable

  25. Cryptographic Hash Functions (Contd...2)

    1. What is the iterated hash function and ideal hash function

    2. What is commitment scheme and its pitfalls

    3. Can we look at MAC construction example

    4. What is the attack and how can we forge MAC

    5. What is Joux's attack

    6. What are multi collisions 1 and 2

    7. What is the multi collision attack and can we look at a demo on meaningful collisions

    8. What is the problem with meaningful collisions and weaker collissions

  26. Cryptography and Network Security - Final Quiz