Souradyuti Paul

{{Short description|Indian cryptographer (born 1976)}}

{{Use dmy dates|date=March 2025}}

{{Use Indian English|date=March 2025}}

{{Infobox scientist

| image =

| image_size = 150px

| name = Souradyuti Paul

| caption =

| birth_date =

| nationality = {{flagicon|India}}Indian

| work_institution = Indian Institute of Technology Bhilai
University of Waterloo
NIST
Katholieke Universiteit Leuven

| alma_mater = Katholieke Universiteit Leuven
Indian Statistical Institute
Jadavpur University

| field = Cryptography

| known_for = Hash Functions
Cryptanalysis
Fast Wide-pipe Hash Mode
Stream Ciphers

| doctoral_advisor = Bart Preneel

| doctoral_students =

| website = http://homes.esat.kuleuven.be/~psourady/

}}

Souradyuti Paul (born 1976) is an Indian cryptologist. Formerly a member of COSIC, he is currently working as an associate professor at Indian Institute of Technology Bhilai{{Cite web|url=https://www.iitgn.ac.in/faculty/comp/souradyuti.htm|title=Souradyuti Paul {{!}} IIT Gandhinagar|website=www.iitgn.ac.in|access-date=2018-12-12}} and a Guest Researcher for the National Institute of Standards and Technology in the United States. He participated in cryptanalysis of RC4, Helix and Py family of ciphers among others. He has co-designed the following ciphers

• RC4A
• RCR-32, RCR-64.

He also contributed to the design of a hash function iteration mode of operation Fast-widepipe.Mridul Nandi and Souradyuti Paul. Speeding Up the Widepipe: Secure and Fast Hashing. In Guang Gong and Kishan Gupta, editor, Indocrypt 2010, Springer, 2010. While working at NIST Dr. Paul has worked towards the development of US government secure hash standard SHA-3 being selected through a public competition.{{Cite web|url=https://www.nist.gov/itl/csd/ct/hash_competition.cfm|title = Cryptographic Hash Algorithm Competition| work=NIST |date = 13 May 2009}}