Professor

Applied Statistics Unit

Indian Statistical Institute

• Modes of operations
• Mathematics of symmetric cipher cryptanalysis
• Symmetric key broadcast encryption
• Design and analysis of collision resistant hash functions
• Design and analysis of symmetric key ciphers
• Analysis of time-memory trade-off attacks
• Cryptographic properties of Boolean functions and S-boxes
• Universal one-way hash functions
• Elliptic curve cryptography
• Pairing based cryptography
• Discrete logarithm computation
• Lattice based cryptography
• Code based cryptography
  
• Another look papers
• Blockchain and cryptocurrency
• Other topics in cryptology
  

• Cryptographic properties of Boolean functions and S-boxes
• Analysis of Boolean functions
• Enumeration of Boolean function sub-classes
• Voting games

• Voting games
  
• Inequality measurement
  
• Order matching algorithms
  

1. Sreyosi Bhattacharyya, Kaushik Nath and Palash Sarkar. Polynomial hashing over prime order fields.  Advances in Mathematics of Communications, 2024 (link) (Highlight: Provides more efficient alternatives to the de facto standard Poly1305 algorithm.)
2. Sebati Ghosh and Palash Sarkar. Breaking Tweakable Enciphering Schemes using Simon's Algorithm.  Designs, Codes, and Cryptography, 2021 (link).
   
3. Sebati Ghosh and Palash Sarkar. Variants of Wegman-Carter Message Authentication Code Supporting Variable Tag Lengths.  Designs, Codes, and Cryptography, 2021 (link). (Highlight: The first work to formalise the problem and provide provable and practical solutions using off-the-shelf block and stream ciphers.)
4. Debrup Chakraborty, Sebati Ghosh, Cuauhtemoc Lopez and Palash Sarkar.  FAST: Disk Encryption and Beyond.  Advances in Mathematics of Communications, 2022 (link). (Highlight: Provides the presently known fastest provably secure algorithm for disk encryption and much more general applications of tweakable enciphering schemes supporting associated data.)
   
5. Sreyosi Bhattacharyya and Palash Sarkar. Improved SIMD Implementation of Poly1305. IET Information Security, 2020 (link).
6. Sebati Ghosh and Palash Sarkar. Evaluating Bernstein-Rabin-Winograd Polynomials. Designs, Codes and Cryptography, 2019 (link).
7. Debrup Chakraborty, Cuauhtemoc Mancillas-Lopez and Palash Sarkar. Disk Encryption: Do We Need to Preserve Length? Journal of Cryptographic Engineering, 2018 (link). (Highlight: Provides very efficient provably secure solutions for disk encryption using deterministic authenticated encryption modulo the lifting of the constraint of length preservation.)
8. Debrup Chakraborty, Sebati Ghosh and Palash Sarkar. A Fast Single-Key Two-Level Universal Hash Function. IACR Transactions on Symmetric Cryptology, 2017 (link). (Highlight: Provides the presently fastest known universal hash function over binary extension fields.)
9. Debrup Chakraborty and Palash Sarkar. On modes of operations of a block cipher for authentication and authenticated encryption. Cryptography and Communications, 2016, (link). (Highlight: Provides AEAD schemes enjoying provable security and efficiency comparable to the famous OCB3 algorithm.)
10. Debrup Chakraborty, Cuauhtemoc Mancillas-Lopez and Palash Sarkar.  STES: A Stream Cipher Based Low Cost Scheme for Securing Stored Data.  IEEE Transactions on Computers, 2015 (link). (Highlight: Provides the first proposals of provably secure and efficient stream cipher based disk encryption scheme with very low hardware footprint.)
11. Debrup Chakraborty, Vicente Hernandez-Jimenez, Palash Sarkar. Another Look at XCB.  Cryptography and Communications, 2015 (link).
12. Palash Sarkar. Modes of Operations for Encryption and Authentication Using Stream Ciphers Supporting an Initialisation Vector.  Cryptography and Communications, 2014 (link). (Highlight: The first work to formalise the problem and provide efficient solutions.)
13.  Palash Sarkar. A New Multi-Linear Universal Hash Family.  Designs, Codes and Cryptography, 2013 (link).
14.  Debrup Chakraborty, Cuauhtemoc Mancillas-Lopez, Francisco Rodriguez-Henriquez and Palash Sarkar. Efficient Hardware Implementations of BRW Polynomials and Tweakable Enciphering Schemes. IEEE Transactions on Computers, 2013 (link). (Highlight: Shows how to exploit inherent parallelism in the definition of BRW polynomials to obtain efficient hardware implementation and as a consequence the hardware implementations of disk encryption schemes using such polynomials)
15.  Palash Sarkar. Tweakable Enciphering Schemes Using Only the Encryption Function of a Block Cipher. Information Processing Letters, 2011 (link).
16. Palash Sarkar. A Trade-Off Between Collision Probability and Key Size in Universal Hashing Using Polynomials. Designs, Codes and Cryptography, 2011 (link).
17. Palash Sarkar. A Simple and Generic Construction of Authenticated Encryption With Associated Data. ACM Transactions on Information and Systems Security, 2010 (link).
18. Palash Sarkar. Pseudo-Random Functions and Parallelizable Modes of Operations of a Block Cipher. IEEE Transactions on Information Theory, 2010 (link). (The AE(AD) constructions are incorrect. Click for updated schemes and implementation details.)
    
19. Palash Sarkar. Efficient Tweakable Enciphering Schemes from (Block-Wise) Universal Hash Functions. IEEE Transactions on Information Theory, 2009 (link).
20. Palash Sarkar. A General Mixing Strategy for the ECB-Mix-ECB Mode of Operation.  Information Processing Letters, 2008 (link).
21. Debrup Chakraborty and Palash Sarkar. A General Construction of Tweakable Block Ciphers and Different Modes of Operations.  IEEE Transactions on Information Theory, 2008 (link).
22. Debrup Chakraborty and Palash Sarkar. HCH: A New Tweakable Enciphering Scheme Using the Hash-Counter-Hash Approach.  IEEE Transactions on Information Theory, 2008 (link).
23. Palash Sarkar. Improving Upon the TET Mode of Operation, ICISC, 2007 (link).
24. Debrup Chakraborty and Palash Sarkar. A New Mode of Encryption Providing A Tweakable Strong Pseudo-Random Permutation, FSE, 2006 (link).

Top

Mathematics of symmetric cipher cryptanalysis
(analysis of linear cryptanalysis, differential cryptanalysis and their several variants)

1. Subhabrata Samajder and Palash Sarkar. Another Look at Key Randomisation Hypotheses.  Designs, Codes, and Cryptography, 2023 (link). (Highlight: Provides formal arguments and simulation results to show that the success probability of linear cryptanalysis is a monotone increasing function of the number of plaintext-ciphertext pairs even under the alternate key randomisation hypotheses.)
   
2. Subhabrata Samajder and Palash Sarkar. Another Look at Success Probability of Linear Cryptanalysis. Advances in Mathematics of Communications, 2019 (link).
3. Subhabrata Samajder and Palash Sarkar. Multiple (Truncated) Differential Cryptanalysis: Explicit Upper Bounds on Data Complexity. Cryptography and Communications, 2018 (link). (Highlight: Performs a rigorous statistical analysis of multiple (truncated) differential cryptanalysis.)
4. Subhabrata Samajder and Palash Sarkar. Correlations Between (Nonlinear) Combiners of Input and Output of Random Functions and Permutations. CSCML, 2023 (link).
5. Subhabrata Samajder and Palash Sarkar. Distinguishing Error of Nonlinear Invariant Attacks. Indocrypt, 2022 (link).
6. Subhabrata Samajder and Palash Sarkar. A New Test Statistic for Key Recovery Attacks Using Multiple Linear Approximations. Mycrypt, 2016 (link).
7. Subhabrata Samajder and Palash Sarkar. Success Probability of Multiple/Multidimensional Linear Cryptanalysis Under General Key Randomisation Hypotheses. Cryptography and Communications, 2018 (link). (Highlight: Performs a general and unified statistical analysis of attacks on block ciphers using several linear approximations.)
   
8. Subhabrata Samajder and Palash Sarkar. Rigorous Upper Bounds on Data Complexities of Block Cipher Cryptanalysis. Journal of Mathematical Cryptology, 2017 (link).(Highlight: Rigorous statistical analysis using Chernoff and Hoeffding bounds to obtain data complexities of various methods for block cipher cryptanalysis.)
9. Subhabrata Samajder and Palash Sarkar. Another Look at Normal Approximations in Cryptanalysis. Journal of Mathematical Cryptology, 2016 (link). (Highlight: Considers concrete versions of some normal approximations used in cryptanalysis and uses Berry-Esseen theorem to derive concrete bounds on the error in approximation. This invalidates some previous analysis of attacks. The paper instead adopts the hypothesis testing based method to analyse such attacks.)

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Symmetric key broadcast encryption

1. Sanjay Bhattacherjee and Palash Sarkar. Reducing Communication Overhead of the Subset Difference Scheme.  IEEE Transactions on Computers, 2016 (link). (Highlight: Provides a parameterised family of symmetric key broadcast encryption scheme which includes the famous Naor-Naor-Lotspiech (NNL) scheme as a special case. By appropriately selecting parameters it is possible to achieve header size smaller than all known schemes while keeping the decryption time constant and at a cost of increasing the user key size.)
2. Sanjay Bhattacherjee and Palash Sarkar. Tree Based Symmetric Key Broadcast Encryption.  Journal of Discrete Algorithms, 2015 (link). (Highlight: Proposes and analyses k-ary tree based broadcast encryption scheme.)
3. Sanjay Bhattacherjee and Palash Sarkar. Concrete Analysis and Trade-Offs for the (Complete Tree) Layered Subset Difference Broadcast Encryption Scheme. IEEE Transactions on Computers, 2014 (link). (Highlight: Formalises and solves optimisation problems on the trade-off between user storage and header size in symmetric key broadcast encryption providing significant improvements to an earlier scheme proposed by Halevy and Shamir.)
4. Sanjay Bhattacherjee and Palash Sarkar. Complete Tree Subset Difference Broadcast Encryption Scheme and its Analysis.  Designs, Codes and Cryptography, 2013. (link). (Highlight: Proposes and performs extensive analysis of the complete tree subset difference method which subsumes the earlier proposal known as the subset difference method made by Naor, Naor and Lotspiech.)

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Design and analysis of collision resistant hash functions

1. Somitra Kumar Sanadhya and Palash Sarkar. A Combinatorial Analysis of Recent Attacks on Step Reduced SHA-2 Family. Cryptography and Communications, 2009 (link). (Highlight: A general analysis of the till then known attacks on SHA-256 exhibiting colliding message pairs for up to 24 rounds.)
2. Somitra Kumar Sanadhya and Palash Sarkar. A New Hash Family Obtained by Modifying the SHA-2 Family. ASIACCS, 2009 (link). (Highlight: Proposed modifications to SHA-2 to improve resistance to the till then known attacks.)
3. Somitra Kumar Sanadhya and Palash Sarkar. New Collision attacks Against Up To 24-step SHA-2 (extended abstract). Indocrypt, 2008 (link). (Highlight: Faster collision attacks against up to 24-step SHA-256 and SHA-512.)
4. Somitra Kumar Sanadhya and Palash Sarkar. Deterministic Constructions of 21-Step Collisions for the SHA-2 Hash Family. ISC, 2008 (link).
5. Somitra Kumar Sanadhya and Palash Sarkar. Non-Linear Reduced Round Attacks Against SHA-2 Hash family. ACISP, 2008 (link).
6. Somitra Kumar Sanadhya and Palash Sarkar. Attacking Reduced Round SHA-256. ACNS, 2008 (link).
7. Somitra Kumar Sanadhya and Palash Sarkar. New Local Collisions for the SHA-2 Hash Family. ICISC, 2007 (link).
8. Pinakpani Pal and Palash Sarkar. PARSHA-256: A Parallelizable Hash Function and a Multithreaded Implementation. FSE, 2003 (link).
9. Wonil Lee, Mridul Nandi, Palash Sarkar, Donghoon Chang, Sangjin Lee and Kouichi Sakurai. A Generalization of PGV-Hash Functions and Security Analysis in Black-Box Model. ACISP, 2004 (link).
10. Somindu C. Ramanna and Palash Sarkar. On Quantifying the Resistance of Concrete Hash Functions to Generic Multi-Collision Attacks. IEEE Transactions on Information Theory, 2011 (link). (Highlight: Extends and analyses the notion of balance introduced by Bellare and Kohno for generic collision attacks to generic multi-collision attacks.)
11. Palash Sarkar and Paul J. Schellenberg. A Parallel Algorithm for Extending Cryptographic Hash Functions. Indocrypt, 2001 (link).
12. Palash Sarkar. Domain Extender for Collision Resistant Hash Functions: Improving Upon Merkle-Damgard Iteration. Discrete Applied Mathematics, 2009 (link). (Highlight: Provides an algorithm to extend a compression function to a collision resistant hash function which performs O(log|x|) padding, thus improving upon the O(|x|) padding required by the Merkle-Damgard algorithm. Here x is the message to be hashed.)

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1. Joydip Mitra and Palash Sarkar. Time-Memory Trade-Off Attacks on Multiplications and T-functions. Asiacrypt, 2004 (link). (Highlight: Breaks concrete proposals for multi-word T-functions by Klimov and Shamir.)
2. Jin Hong, Dong Hoon Lee, Seongtaek Chee and Palash Sarkar. Vulnerability of Nonlinear Filter Generators Based on Linear Finite State Machines. FSE, 2004 (link).
3. Palash Sarkar. Hiji-bij-bij: A New Stream Cipher with a Self-Synchronizing Mode of Operation. Indocrypt, 2003 (link).
4. Palash Sarkar. The Filter-Combiner Model for Memoryless Synchronous Stream Ciphers. CRYPTO, 2002. (link).
5. Palash Sarkar and Subhamoy Maitra. Efficient Implementation of ``Large'' Stream Cipher Systems. CHES, 2001 (link).
6. Sanjay Burman and Palash Sarkar. An Efficient Algorithm for Software Generation of Linear Binary Recurrences. Applicable Algebra in Engineering, Communication and Computing, 2004 (link).

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Analysis of time-memory trade-off attacks

1. Sourav Mukhopadhyay and Palash Sarkar. Hardware Architecture and Cost/time/data Trade-off for Generic Inversion of One-Way Function. Computacion y Sistemas, Special Issue on Applied Cryptography & Data Security, 2009 (link).
2. Sourav Mukhopadhyay and Palash Sarkar. On the Effectiveness of TMTO and Exhaustive Search Attacks. IWSEC, 2006 (link).
3. Sourav Mukhopadhyay and Palash Sarkar. Application of LFSRs for Parallel Sequence Generation in Cryptologic Algorithms. ICCSA, 2006 (link).
4. Jin Hong and Palash Sarkar. New Applications of Time Memory Data Tradeoffs. Asiacrypt, 2005 (link). (Highlight: Analyses several important implications of TMTO attacks including the fact that stream ciphers with IV shorter than the key are vulnerable to TMTO attacks.)
5. Alex Biryukov, Sourav Mukhopadhyay and Palash Sarkar. Improved Time-Memory Trade-offs with Multiple Data. SAC, 2005 (link).
6. Sourav Mukhopadhyay and Palash Sarkar. Application of LFSRs in Time/Memory Trade-Off Cryptanalysis. WISA, 2005 (link).

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Cryptographic properties of Boolean functions and S-boxes
(nonlinearity, resiliency, strict avalanche criterion, propagation characteristics and other properties)

1. Kishan Chand Gupta and Palash Sarkar. Computing Partial Walsh Transform from the Algebraic Normal Form of a Boolean Function. IEEE Transactions on Information Theory, 2009 (link).
2. Palash Sarkar and Subhamoy Maitra. Balancedness and Correlation Immunity of Symmetric Boolean Functions. Discrete Mathematics, 2007 (link).
3. Kishan Chand Gupta and Palash Sarkar. Towards a General Correlation Theorem. IEEE Transactions on Information Theory, 2005 (link).(Highlight: A general correlation theorem is proved (of which some earlier results proved by Nyberg are special cases) and applied to various constructions of cryptographic interest.)
4. Kishan Chand Gupta and Palash Sarkar. Improved Construction of Nonlinear Resilient S-Boxes. IEEE Transactions on Information Theory, 2005 (link). (Highlight: Use of the Griesmer bound for linear codes.)
5. Kishan Chand Gupta and Palash Sarkar. Construction of Perfect Nonlinear and Maximally Nonlinear Multi-Output Boolean Functions Satisfying Higher Order Strict Avalanche Criteria. IEEE Transactions on Information Theory, 2004 (link). (Highlight: Use of bilinear forms, symplectic matrices and one-factorisation of a complete graph.)
6. Kishan Chand Gupta and Palash Sarkar. Construction of High Degree Resilient S-boxes With Improved Nonlinearity. Information Processing Letters, 2005 (link).
7. Palash Sarkar and Subhamoy Maitra. Construction of Nonlinear Resilient Functions Using ``Small'' Affine Functions. IEEE Transactions on Information Theory, 2004 (link). (Highlight: Provides refined techniques to construct cryptographically useful Boolean functions using small affine functions.)
8. Palash Sarkar and Subhamoy Maitra. Efficient Implementation of Cryptographically Useful Large Boolean Functions. IEEE Transactions on Computers, 2003 (link). (Highlight: The first work to describe a hardware architecture for implementing large Boolean functions of cryptographic interest.)
9. Subhamoy Maitra and Palash Sarkar. Maximum Nonlinearity of Symmetric Boolean Functions on Odd Number of Variables. IEEE Transactions on Information Theory, 2002 (link). (Highlight: Establishes the upper bound on the nonlinearity of symmetric Boolean functions on odd number of variables and characterises the functions for which the upper bound is achieved.)
10. Claude Carlet and Palash Sarkar. Spectral Domain Analysis of Correlation Immune and Resilient Boolean Functions. Finite Fields and their Applications, 2002 (link). (Highlight: Provides weight divisibility results for the Walsh transform of correlation immune and resilient Boolean functions which results in non-trivial upper bounds on the non-linearity of such functions.)
11. Subhamoy Maitra and Palash Sarkar. Characterization of Symmetric Bent Functions -- An Elementary Proof. Journal of Combinatorial Mathematics and Combinatorial Computing, 43 (2002), 227-230.
12. Subhamoy Maitra and Palash Sarkar. Cryptographically Significant Boolean Functions with Five Valued Walsh Spectra. Theoretical Computer Science, 2002 (link).
13. Palash Sarkar and Subhamoy Maitra. Cross-Correlation Analysis of Cryptographically Useful Boolean Functions and S-Boxes. Theory of Computing Systems, 2002 (link).
14. Subhamoy Maitra and Palash Sarkar. Cryptographic Modifications of Patterson-Weidemann Functions. IEEE Transactions on Information Theory, 2002 (link). (Highlight: Answers some open questions about Boolean functions by modifying bent and Patterson-Wiedemann functions to achieve cryptographically useful properties.)
15. Palash Sarkar. A note on the spectral characterization of correlation immune Boolean functions.  Information Processing Letters, 2000 (link).
16. Subhamoy Maitra, Palash Sarkar. Hamming Weights of Correlation Immune Boolean Functions.  Information Processing Letters, 1999 (link).
17. Enes Pasalic, Subhamoy Maitra, Thomas Johansson, and Palash Sarkar, New Constructions of Resilient and Coorelation Immune Boolean Functions Achieving the Upper Bound on Nonlinearity. Electronic Notes in Discrete Mathematics, 2001 (link).
18. Kishan Chand Gupta and Palash Sarkar. Efficient Representation and Software Implementation of Resilient Maiorana-McFarland S-Boxes. WISA, 2004 (link). (Highlight: The first work to consider the software implementation of resilient Maiorana-McFarland S-Boxes.)
19. Palash Sarkar and Subhamoy Maitra. Nonlinearity Bounds and Constructions of Resilient Boolean Functions. Crypto, 2000 (link).
20. Palash Sarkar and Subhamoy Maitra. Construction of Nonlinear Boolean Functions with Important Cryptographic Properties. Eurocrypt, 2000 (link).
21. Subhamoy Maitra and Palash Sarkar. Highly Nonlinear Resilient Functions Optimizing Siegenthaler's Inequality. Crypto, 1999 (link).
22. Subhamoy Maitra and Palash Sarkar. Enumeration of Correlation Immune Boolean Functions. ACISP, 1999 (link).

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Universal one-way hash functions

1. Palash Sarkar. Construction of universal one-way hash functions: Tree hashing revisited. Discrete Applied Mathematics, 2007 (link).
2. Palash Sarkar. Masking Based Domain Extenders for UOWHFs: Bounds and Constructions. IEEE Transactions on Information Theory, 2005 (link).
3. Palash Sarkar. Domain Extenders for UOWHF: A Finite Binary Tree Algorithm. Journal of Universal Computer Science, 2005 (link).
4. Palash Sarkar. Masking Based Domain Extenders for UOWHFs: Bounds and Constructions. Asiacrypt, 2004 (link).

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Elliptic curve cryptography

1. Palash Sarkar. Computing square roots faster than the Tonelli-Shanks/Bernstein algorithm. Advances in Mathematics of Communications, 2024 (link).
2. Kaushik Nath and Palash Sarkar. Kummer versus Montgomery Face-off over Prime Order Fields. ACM Transactions on Mathematical Software, 2022 (link). (Highlight: Proposes new Kummer lines at high security levels and compares performance of Kummer lines and Montgomery form elliptic curves.)
3. Kaushik Nath and Palash Sarkar. Security and Efficiency Trade-offs for Elliptic Curve Diffie-Hellman at the 128-bit and 224-bit Security Levels. Journal of Cryptographic Engineering, 2022 (link). (Highlight: Proposes new pairs of Montgomery-Edwards curves at the 128-bit and 224-bit security level. Implementation results show that computations over the new curve at the 128-bit security level is faster than those over the de facto standard Curve25519.)
4. Kaushik Nath and Palash Sarkar. Efficient 4-way Vectorizations of the Montgomery Ladder. IEEE Transactions on Computers, 2022 (link). (Highlight: Provides new algorithms for 4-way vectorisation of Montgomery ladder computation and their SIMD implementations.)
5. Kaushik Nath and Palash Sarkar. Reduction Modulo 2^{448}-2^{224}-1. Mathematical Cryptology, 2020 (link).
6. Kaushik Nath and Palash Sarkar. Efficient Arithmetic in (pseudo-)Mersenne Prime Order Fields. Advances in Mathematics of Communications, 2022 (link). (Highlight: Describes algorithms accompanied by formal statements and detailed proofs of correctness for modulo reduction for primes of certain forms which are of interest to elliptic curve cryptography. Also provides extensive hand optimised assembly implementations of the relevant field arithmetic operations.)
7. Kaushik Nath and Palash Sarkar. Efficient Elliptic Curve Diffie-Hellman Computation at the 256-bit Security Level. IET Information Security, 2020 (link). (Highlight: Proposes new pairs of Montgomery-Edwards curves for efficient elliptic curve cryptography at the 256-bit security level. Also provides extensive hand optimised implementations of the Diffie-Hellman computations.)
8. Sabyasachi Karati and Palash Sarkar. Kummer for Genus One over Prime Order Fields. Journal of Cryptology, 2020 (link). (Highlight: The first work to propose concrete Kummer lines at the 128-bit security level and perform SIMD implementations to demonstrate the advantage of Kummer lines over Montgomery form curves for vectorised implementations.)
9. Sabyasachi Karati and Palash Sarkar. Kummer for Genus One over Prime Order Fields, Asiacrypt, 2017 (link). (Highlight: This paper was recommended by the program chairs of the conference for invitation to the Journal of Cryptology.)
10. Sabyasachi Karati and Palash Sarkar. Connecting Legendre with Kummer and Edwards. Advances in Mathematics of Communications, 2019 (link).
11. Pradeep Kumar Mishra, Pinakpani Pal and Palash Sarkar. Towards Minimizing Memory Requirement for Implementation of Hyperelliptic Curve Cryptosystems. ISPEC, 2007 (link).
12. Palash Sarkar, Pradeep Kumar Mishra and Rana Barua. New Table Look-up Methods for Faster Frobenius Map Based Scalar Multiplication Over GF(p^n). ACNS, 2004 (link).
13. Pradeep Kumar Mishra and Palash Sarkar. Application of Montgomery's Trick to Scalar Multiplication for Elliptic and Hyperelliptic Curves Using a Fixed Base Point. PKC, 2004 (link).
14. Palash Sarkar, Pradeep Kumar Mishra and Rana Barua. A Parallel Algorithm for Computing Simultaneous Inversions with Application to Elliptic Curve Scalar Multiplication. IEEE MSCAS, 2003 (link).
15. Pradeep Kumar Mishra and Palash Sarkar. Parallelizing Explicit Formula for Arithmetic in the Jacobian of Hyperelliptic Curves. Asiacrypt, 2003 (link).

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Pairing based cryptography
(identity-based encryption, hierarchical identity-based encryption, identity-based broadcast encryption, implementation of pairings)

1. Somindu C. Ramanna, Palash Sarkar. Efficient Adaptively Secure IBBE from the SXDH Assumption. IEEE Transactions on Information Theory, 2016 (link). (Highlight: Describes the first constructions of identity-based broadcast encryption using Type-3 pairings, which can be proved secure against adaptive-identity attacks based on the Symmetric eXternal Diffie-Hellman assumption achieving a security degradation which is not exponential in the size of the target identity set.)
2. Somindu C. Ramanna and Palash Sarkar. Efficient (Anonymous) Compact HIBE From Standard Assumptions. ProvSec, 2014 (link).
3. Somindu C. Ramanna and Palash Sarkar. Anonymous Constant-Size Ciphertext HIBE From Asymmetric Pairings. IMACC, 2013 (link).
4. Somindu C. Ramanna, Sanjit Chatterjee and Palash Sarkar.  Variants of Waters' Dual System Primitives Using Asymmetric Pairings. PKC, 2012 (link).
5. M. Prem Laxman Das and Palash Sarkar. Pairing Computation on Twisted Edwards Form Elliptic Curves. Pairing, 2008 (link). (Highlight: The first work to systematically consider pairing computation over twisted Edwards form Elliptic curves.)
6. Palash Sarkar and Sanjit Chatterjee. Construction of a Hybrid Hierarchical Identity Based Encryption Protocol Secure Against Adaptive Attacks (Without Random Oracle). ProvSec, 2007 (link). (Highlight: Describes the most efficient hybrid hierarchical identity based encryption (HIBE) protocol which is secure in the full model without using random oracles and whose security is based on the DBDH problem.)
7. Sanjit Chatterjee and Palash Sarkar. HIBE with Short Public Parameters Without Random Oracle. Asiacrypt, 2006 (link).
8. Sanjit Chatterjee and Palash Sarkar. New Constructions of Constant Size Ciphertext HIBE Without Random Oracle. ICISC, 2006 (link).
9. Sanjit Chatterjee and Palash Sarkar. Practical hybrid (hierarchical) identity-based encryption schemes based on the decisional bilinear Diffie-Hellman assumption. International Journal of Applied Cryptography, 2013 (link).
10. Sanjit Chatterjee and Palash Sarkar. Constant Size Ciphertext HIBE in the Augmented Selective-ID Model and its Extensions. Journal of Universal Computer Science, 2007 (link).
11. Sanjit Chatterjee and Palash Sarkar. Generalization of the Selective-ID Security Model for HIBE Protocols. PKC, 2006 (link).
12. Sanjit Chatterjee and Palash Sarkar. Trading Time for Space: Towards an Efficient IBE Scheme with Short(er) Public Parameters in the Standard Model. ICISC, 2005 (link).
13. https://link.springer.com/chapter/10.1007/11734727_33
14. Sanjit Chatterjee, Palash Sarkar and Rana Barua. Efficient Computation of Tate Pairing in Projective Coordinate Over General Characteristic Fields. ICISC, 2004 (link). (Highlight: The first paper to propose encapsulated point and line computation for Tate pairing.)
15. Ratna Dutta, Rana Barua and Palash Sarkar. Provably Secure Authenticated Tree Based Group Key Agreement. ICICS, 2004 (link).
16. Rana Barua, Ratna Dutta and Palash Sarkar. Extending Joux's Protocol to Multiparty Key Agreement. Indocrypt, 2003 (link).
17. Ratna Dutta and Rana Barua and Palash Sarkar. Pairing-Based Cryptographic Protocols: A Survey. IACR ePrint Archive, 2004 (link).

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Discrete logarithm computation
(mainly over finite fields, but also includes elliptic curves, hyperelliptic curves and class group computation)

1. Madhurima Mukhopadhyay, Palash Sarkar, Shashank Singh and  Emmanuel Thome. New discrete logarithm computation for the medium prime case using the function field sieve. Advances in Mathematics of Communications, 2022 (link). (Highlight: Reports a new record discrete logarithm computation over a 1051-bit field having a 22-bit characteristic.)
2. Madhurima Mukhopadhyay and Palash Sarkar. Faster Initial Splitting for Small Characteristic Composite Extension Degree Fields. Finite Fields and their Applications, 2020 (link).
3. Palash Sarkar and Shashank Singh. A Unified Polynomial Selection Method for the (Tower) Number Field Sieve Algorithm. Advances in Mathematics of Communications, 2019 (link). (Highlight: Presents a unified polynomial selection method for discrete logarithm computation using the number field sieve algorithm. The new method subsumes allpreviously known methods and for certain classes of primes the new method provides the best known complexity.)
4. Palash Sarkar and Shashank Singh. A simple method for obtaining relations among factor basis elements for special hyperelliptic curves. Applicable Algebra in Engineering, Communication and Computing, 2017 (link).
5. Palash Sarkar and Shashank Singh. A New Method for Decomposition in the Jacobian of Small Genus Hyperelliptic Curves. Designs, Codes and Cryptography, 2017 (link). (Highlight: Improves upon a 17-year old method due to Gaudry.)
6. Palash Sarkar and Shashank Singh. Fine Tuning the Function Field Sieve Algorithm for the Medium Prime Case.  IEEE Transactions on Information Theory, 2016 (link). (Highlight: Introduces new ideas supported by detailed analysis to improve the efficiency and coverage of the function field sieve algorithm for discrete logarithm computation. Also reports two record discrete logarithm computations.)
7. Madhurima Mukhopadhyay and Palash Sarkar. Pseudo-Random Walk on Ideals: Practical Speed-Up in Relation Collection for Class Group Computation. CSCML, 2023 (link).
8. Madhurima Mukhopadhyay and Palash Sarkar. Combining Montgomery Multiplication with Tag Tracing for the Pollard Rho Algorithm in Prime Order Fields. SPACE, 2023 (link).
9. Palash Sarkar and Shashank Singh. A General Polynomial Selection Method and New Asymptotic Complexities for the Tower Number Field Sieve Algorithm. Asiacrypt, 2016 (link).
10. Alfred Menezes, Palash Sarkar, Shashank Singh. Challenges with Assessing the Impact of NFS Advances on the Security of Pairing-based Cryptography. Mycrypt, 2016 (link).
11. Palash Sarkar and Shashank Singh. New Complexity Trade-Offs for the (Multiple) Number Field Sieve Algorithm in Non-Prime Fields. Eurocrypt, 2016 (link).

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Lattice based cryptography

1. Neal Koblitz, Subhabrata Samajder, Palash Sarkar and Subhadip Singha. Concrete Analysis of Approximate Ideal-SIVP to Decision Ring-LWE Reduction. Advances in Mathematics of Communications, 2022 (link). (Highlight: Performs a detailed concrete analysis of the seminal worst-to-average case reduction by Lyubashevsky, Peikert, and Regev from approximate SIVP to DLWE problem in ideal lattices. Concrete analyses of a number of other related reductions are also performed. All of these concrete analyses show that such reductions do not provide any security assurance for practical cryptosystems based on ideal lattices.)
2. Palash Sarkar and Subhadip Singha. Classical Reduction of GapSVP to LWE: A Concrete Security Analysis. Advances in Mathematics of Communications, 2023 (link).
3. Palash Sarkar and Subhadip Singha. Verifying Solutions to LWE with Implications for Concrete Security. Advances in Mathematics of Communications, 2021 (link).

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1. Sreyosi Bhattacharyya, Palash Sarkar. Concrete Time/Memory Trade-Offs in Generalised Stern's ISD Algorithm. INDOCRYPT, 2023 (link).

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1. Sanjit Chatterjee, Neal Koblitz, Alfred Menezes, Palash Sarkar. Another Look at Tightness II: Practical Issues in Cryptography. Mycrypt, 2016 (Recipient of the best paper award) (link).(Highlight: Discusses nontightness of security reductions in connection with complexity leveraging, HMAC, lattice-based cryptography, identity-based encryption, and hybrid encryption.)
2. Sanjit Chatterjee, Alfred Menezes and Palash Sarkar. Another Look at Tightness. SAC, 2011 (link). (Highlight: The first work to systematically examine problems with nontight security reductions arising in the multi-user setting. Problematic issues are highlighted for deterministic MAC schemes, network authentication, aggregate MACs, authenticated encryption schemes, disk encryption schemes, and stream ciphers.)

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1. Palash Sarkar. A New Blockchain Proposal Supporting Multi-Stage Proof-of-Work. Journal of Blockchain Research, 2022 (link). (Highlight: Proposes a new blockchain protocol which alleviates the scaling problem of the Bitcoin cryptocurrency.)
2. A paper on the link between cryptocurrency and voting games.

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1. Palash Sarkar. On Some Connections Between Statistics and Cryptology. Journal of Statistical Planning and Inference, 2014 (link).
2. Palash Sarkar and Douglas R. Stinson. Frameproof and IPP Codes. Indocrypt, 2001 (link).
3. Sanjit Chatterjee and Palash Sarkar. Identity-Based Encryption and Hierarchical Identity-Based Encryption. Book chapter in Identity-Based Cryptography, IOS Press, 2008 (link).
4. Palash Sarkar. Overview of Cryptographic Primitives for Secure Communication. Book chapter in Wireless Security and Cryptography: Specifications and Implementations, CRC-Press, ISBN:~084938771X, 2007.
5. Palash Sarkar. A Sketch of Modern Cryptology: The Art and Science of Secrecy Systems. Resonance -- Journal of Science Education, 2000 (link).

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Analysis of Boolean functions

1. Aniruddha Biswas and Palash Sarkar. A Lower Bound on the Constant in the Fourier Min-Entropy/Influence Conjecture. (link). (Highlight: Provides the first non-trivial lower bound on the universal constant in the Fourier Min-Entropy/Influence Conjecture.)
2. Aniruddha Biswas and Palash Sarkar. Influence of a Set of Variables on a Boolean Function, SIAM Journal of Discrete Mathematics, 2023 (link). (Highlight: Introduces and extensively analyses the definition of influence of a set of variables on a Boolean function based on the auto-correlation function.)
3. Aniruddha Biswas and Palash Sarkar. On The ``Majority is Least stable'' Conjecture, Information Processing Letters, 2023 (link). (Highlight: Settles the ``Majority is Least stable'' Conjecture.)
4. Aniruddha Biswas and Palash Sarkar. Separation Results for Boolean Function Classes, Cryptography and Communications, 2021 (link).

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1. Aniruddha Biswas and Palash Sarkar. Counting unate and balanced monotone Boolean functions. (link).

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1. Sanjay Bhattacherjee and Palash Sarkar. Voting Games to Model Protocol Stability and Security of Proof-of-Work Cryptocurrencies. GameSec, 2022 (link). (Highlight: The first paper to use voting games to model security and protocol stability of proof-of-work cryptocurrencies.)
2. Sanjay Bhattacherjee and Palash Sarkar. Weighted Voting Procedure having a Unique Blocker. International Journal of Game Theory, 2021 (link). (Highlight: Uses the formalism of voting games to perform a comprehensive analysis of the voting procedure in the Goods and Services Tax Council of India, and provides suggestions for improving the voting procedure.)
3. Sanjay Bhattacherjee and Palash Sarkar. Correlation and Inequality in Weighted Majority Voting Games, pp 161--191. In Deprivation, Inequality and Polarization. Economic Studies in Inequality, Social Exclusion and Well-Being, Springer, 2019 (link).
   
4. Rana Barua, Satya R. Chakravarty and Palash Sarkar. Measuring P-Power of Voting. Journal of Economic Theory and Social Development, Volume 1, Number 1, Pages 81--91, 2012.
5. Rana Barua, Satya R. Chakravarty and Palash Sarkar. Minimal-Axiom Characterizations of the Coleman and Banzhaf Indices of Voting Power. Mathematical Social Sciences, 2009 (link).
6. Rana Barua, Satya R. Chakravarty, Sonali Roy and Palash Sarkar. A Characterization and Some Properties of the Banzhaf-Coleman Sensitivity Index. Games and Economic Behaviour, 2004 (link). (Highlight: Uses Walsh transform to analyse voting power.)

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1. Satya R. Chakravarty and Palash Sarkar. Notes on the postulate of the monotonicity in distance in inequality. Bulletin of Economic Research, 2022 (link).
2. Satya R. Chakravarty and Palash Sarkar. Inequality minimising subsidy and taxation.  Economic Theory Bulletin, 2022 (link).
3. Satya R. Chakravarty and Palash Sarkar. Designing income distributions with specified inequalities. Economic Theory Bulletin, 2021 (link).
4. Satya R. Chakravarty and Palash Sarkar. An Inequality Paradox: Relative versus Absolute Indices?  Metron, 2021 (link).
5. Satya R. Chakravarty and Palash Sarkar. New Perspectives on the Gini and Bonferroni Indices of Inequality.  Social Choice and Welfare, 2021 (link).

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1. Sanjay Bhattacherjee and Palash Sarkar. On Using Proportional Representation Methods as Alternatives to Pro-rata Based Order Matching Algorithms in Stock Exchanges. Computational Economics, 2024 (link).

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1. Palash Sarkar and Paul J. Schellenberg. Construction of Symmetric Balanced Squares with Blocksize More than One. Designs, Codes, and Cryptography, 2003 (link).
2. Palash Sarkar and Bimal K. Roy. Construction of Nearly Balanced Uniform Repeated Measurement Designs,  Bulletin of the Calcutta Statistical Association, 1995 (link).

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1. Palash Sarkar. Computing Shifts in 90/150 Cellular Automata Sequences. Finite Fields and their Applications, 2003 (link).
2. Palash Sarkar. A brief history of cellular automata. ACM Computing Surveys, 2000 (link).
3. Palash Sarkar, Rana Barua. Multidimensional Sigma-Automata, Pi-Polynomials and Generalised S-Matrices. Theoretical Computer Science, 1998 (link).
4. Palash Sarkar and Rana Barua. The set of reversible 90/150 cellular automata is regular. Discrete Applied Mathematics, 1998 (link).
5. Palash Sarkar. \sigma^{+}-Automata on Square Grids, Complex Systems, 1998 (link).

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1. Palash Sarkar. Aspects of Inductive Inference in Statistics and Machine Learning. In A Tribute to the Legend of Professor C. R. Rao, Springer, 2021, (link).
2. Palash Sarkar. Carvakism Redivivus. Newsletter of the American Philosophical Association on Asian and Asian-American Philosophers and Philosophies, 2018 (link).
3. Palash Sarkar and Prasanta S. Bandyopadhyay. Simpson's Paradox: A Singularity of Statistical and Inductive Inference. Arxiv, 2021 (link).

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1. Palash Sarkar. Can Efficient Detection and Isolation Control an Epidemic? Arxiv, 2020 (link).
2. Palash Sarkar. Pushdown Automaton with the Ability to Flip its Stack.  Electronic Collquium on Computational Complexity, 2001 (link).

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