Ph.D, MSc

Dr. Srinivasan C. currently serves as Assistant Professor at TIFAC-CORE in Cyber Security, Coimbatore Campus. His areas of research include Cryptology, Coding and Information Theory.


  • Linear Algebra
  • Coding and Information Theory
  • Integral Transforms and Complex Analysis
  • Cryptography

Funded Projects:

  • “Development of Secure Authenticated Encryption Scheme for Lightweight Applications”, Sponsored by DeitY, Delhi - The objective of the project is to design a secure authenticated encryption algorithm for lightweight applications. This algorithm can be implemented on a variety of lightweight platforms like mobile devices, smart cards, RFID devices etc. This implementation will have an impact on the level of security as well as the speed, which however can be suitably tailored by fine tuning of security versus efficiency requirements.
  • “An Project on Cryptography” Sponsored by ISRO - The aim of the project is to study design aspects and cryptanalysis of symmetric key cryptosystems.


Publication Type: Journal Article

Year of Publication Title


Dr. M. Sethumadhavan, ,, Megha, P., Dr. Sindhu M., and Dr. Srinivasan C., “Hash-One: a lightweight cryptographic hash function”, IET Information Security, vol. 10, no. 5, pp. 225-231(6), 2016.[Abstract]

The increased demand for lightweight applications has triggered the need for appropriate security mechanisms in them. Lightweight cryptographic hash functions are among the major responses toward such a requirement. The authors thus have a handful of such hash functions such as QUARK, PHOTON, SPONGENT and GLUON introduced already. The cryptanalysis of these hash functions is crucial in analysing their strength and often calls for improvement in designs. Their performance, are also to be taken care of, in terms of both software and hardware implementations. Here, they propose a lightweight hash function with reduced complexity in terms of hardware implementation, capable of achieving standard security. It uses sponge construction with permutation function involving the update of two non-linear feedback shift registers. Thus, in terms of sponge capacity it provides at least 80 bit security against generic attacks which is acceptable currently. More »»


Dr. Srinivasan C., Pillai, U. U., K.V., L., and Dr. M. Sethumadhavan, “Cube Attack on Stream Ciphers using a Modified Linearity Test”, Journal of Discrete Mathematical Sciences and Cryptography, vol. 18, pp. 301-311, 2015.[Abstract]

Abstract: There have been various attempts to attack reduced variants of Trivium stream cipher using cube attack. During the preprocessing phase of cube attack, we need to test the linearity of a superpoly. The linearity testing problem is to check whether a function is close to linear by asking oracle queries to the function. This is the BLR linearity test for Boolean functions, which has a time complexity of O(22k + c) cipher operations, where k is the length of the key and c is the size of the cube. In this paper we present a method which is supposed to be a sufficient condition for testing a superpoly for linearity in F<inf>2</inf> with a time complexity O(2c + 1 (k2 + k)). Our analysis on Trivium cipher reduced to 576 rounds using cube attack gives 69 extremely sparse linearly independent linear equations for smaller cubes, which recovers 69 bits of the key and reduces the attack complexity in the online phase to 211. © 2015, Taru Publications.

More »»


Dr. Srinivasan C., K.V., L., and Dr. M. Sethumadhavan, “Measuring diffusion in stream ciphers using statistical testing methods”, Defence Science Journal, vol. 62, pp. 6-10, 2012.[Abstract]

Confusion and diffusion suggested by Claude Shannon are two techniques that symmetric key ciphers should satisfy to prevent cryptanalysis. Diffusion dissipates the statistical properties of the plaintext over the whole ciphertext. For a block cipher, each bit of the output ciphertext block changes with probability one half for any flipped bit in the input plaintext block, implying the cipher to have good diffusion properties. This definition with slight modification can also be applied to stream ciphers but here it is enough to make sure the following: (i) to ensure an overall change in the output keystream with probability half for any flipped bit in the key-IV bit sequence, and (ii) to verify that every bit in the output keystream changes with probability one half for any single bit flip in the key-IV bit sequence. Here we insist on using these tests together for measuring diffusion in stream ciphers. Based on this we have examined the level of diffusion exhibited by some of the eSTREAM candidates and the result is given in this paper. © 2012, DESIDOC.

More »»


Dr. M. Sethumadhavan, Dr. Sindhu M., Dr. Srinivasan C., and Kavitha, C., “An algorithm for k-error joint linear complexity of binary multisequences”, Journal of Discrete Mathematical Sciences and Cryptography, vol. 11, pp. 297-304, 2008.[Abstract]

Abstract Our aim is to find some of the analogues of results related to k-error linear complexity of single sequences to the case of multisequences over GF(2). This paper presents algorithms for finding the joint linear complexity and the k-error joint linear complexity of m-fold binary multisequences of period 2 n . More »»

Publication Type: Book Chapter

Year of Publication Title


A. S. Raj and Dr. Srinivasan C., “Analysis of Algebraic Attack on TRIVIUM and Minute Modification to TRIVIUM”, in Advances in Network Security and Applications: 4th International Conference, CNSA 2011, Chennai, India, July 15-17, 2011, D. C. Wyld, Wozniak, M., Chaki, N., Meghanathan, N., and Nagamalai, D., Eds. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011, pp. 35–42.[Abstract]

In recent times, each user needs to secure the information from unwanted disclosure of secret. Encryption is the most wildly used technique to secure the information. LFSR based cipher systems called stream ciphers are commonly used for applications which requires high speed encryption and implementation. Even though these systems provide secrecy to information stream ciphers are highly vulnerable to attacks. The securities of these systems are calculated mostly in terms of correlation attacks and algebraic attacks. In these attacks the key is found by solving this multivariable system of equations. This paper presents a careful analysis on Stream Cipher TRIVIUM. The study has been performed on how the equations are generated and how much they are vulnerable to various attacks. Finally a minor variation has been made on TRIVIUM to prevent algebraic attack by guessing apposite nonlinear variables. Here propose a new design to the key generation of Trivium that has better correlation properties.

More »»


Dr. Srinivasan C., K.V., L., and Dr. M. Sethumadhavan, “Complexity Measures of Cryptographically Secure Boolean Functions”, in Cyber Security, Cyber Crime and Cyber Forensics: Applications and Perspectives, IGI Global, 2010.[Abstract]

Boolean functions are used in modern cryptosystems for providing confusion and diffusion. To achieve required security by resistance to various attacks such as
algebraic attacks, correlation attacks, linear, differential attacks, several criteria for Boolean functions have been established over years by cryptographic community. These criteria include non linearity, avalanche criterion and correlation immunity and the like. The chapter is an attempt to present state of the art on properties of such Boolean functions and to suggest several directions for further research.

More »»