Igors Stepanovs
I am interested in practice-oriented cryptography. My ongoing and recently completed projects focus on providing formal security analysis of novel cryptographic algorithms that are deployed in widely used software.
I currently work at Amazon. Previously I worked as a postdoctoral researcher in the Applied Cryptography Group at ETH Zürich led by Kenny Paterson. I earned a PhD in Computer Science at UC San Diego advised by Mihir Bellare. Prior to starting my doctoral studies, I obtained BSc and MSc in Computer Science at University of Latvia, and MSc in Mathematics of Cryptography and Communcations at Royal Holloway, University of London.
I worked as a software developer during my university studies. In one of my roles, I participated in the development of a whitebox cryptography library. I provide more information in my LinkedIn and CV.
Analysis of the Telegram Key Exchange
Martin R. Albrecht, Lenka Mareková, Kenneth G. Paterson, Eyal Ronen, Igors Stepanovs.
EUROCRYPT 2025.
Lenka's talk and slides at EC 2025.
Symmetric Signcryption and E2EE Group Messaging in Keybase
Joseph Jaeger, Akshaya Kumar, Igors Stepanovs.
EUROCRYPT 2024.
Akshaya's talk and PowerPoint slides at EC 2024; Akshaya's talk and slides at RWC 2025.
Four Attacks and a Proof for Telegram
Martin R. Albrecht, Lenka Mareková, Kenneth G. Paterson, Igors Stepanovs.
IEEE S&P 2022 (Distinguished Paper Award).
webpage; Lenka's talk at IEEE S&P 2022; my slides at Joint Latvian-Estonian Theory Days 2022; my talk and slides at RWC 2022; my comments in popular press.
Security under Message-Derived Keys: Signcryption in iMessage
Mihir Bellare, Igors Stepanovs.
EUROCRYPT 2020.
my pre-recorded talk and slides, and live talk at EC 2020.
On the Security of Two-Round Multi-Signatures
Manu Drijvers, Kasra Edalatnejad, Bryan Ford, Eike Kiltz, Julian Loss, Gregory Neven, Igors Stepanovs.
IEEE S&P 2019.
Manu's talk, slides, and talk preview at IEEE S&P 2019.
Optimal Channel Security Against Fine-Grained State Compromise: The Safety of Messaging
Joseph Jaeger, Igors Stepanovs.
CRYPTO 2018.
Joseph's talk and slides at CRYPTO 2018.
Forward-Security under Continual Leakage
Mihir Bellare, Adam O'Neill, Igors Stepanovs.
CANS 2017.
Ratcheted Encryption and Key Exchange: The Security of Messaging
Mihir Bellare, Asha Camper Singh, Joseph Jaeger, Maya Nyayapati, Igors Stepanovs.
CRYPTO 2017.
Joseph's talk at CRYPTO 2017.
New Negative Results on Differing-Inputs Obfuscation
Mihir Bellare, Igors Stepanovs, Brent Waters.
EUROCRYPT 2016.
my (truncated) talk and slides at EC 2016.
Contention in Cryptoland: Obfuscation, Leakage and UCE
Mihir Bellare, Igors Stepanovs, Stefano Tessaro.
TCC 2016-A.
Stefano's talk at the Simons Workshop on Securing Computation; my slides (combined for two papers) at TCC 2016-A.
Point-Function Obfuscation: A Framework and Generic Constructions
Mihir Bellare, Igors Stepanovs.
TCC 2016-A.
my slides (combined for two papers) at TCC 2016-A.
Poly-Many Hardcore Bits for Any One-Way Function and a Framework for Differing-Inputs Obfuscation
Mihir Bellare, Igors Stepanovs, Stefano Tessaro.
ASIACRYPT 2014.
my slides at AC 2014.
Advising and Academic Service
Advising: Tijana Klimovic (ETH Zürich, MSc thesis, Mar 2021–Sep 2021). "Modular Design of the Messaging Layer Security (MLS) Protocol". Co-Advisor: Kenneth G. Paterson.
Program committee (PC) memberships for scientific conferences:
Sub-reviewing for scientific conferences:
- 2025: CRYPTO
- 2022: CRYPTO, ASIACRYPT, TCC
- 2021: CRYPTO
- 2020: PKC, CRYPTO, ASIACRYPT
- 2019: TCC
- 2017: EUROCRYPT, ICALP, CRYPTO, MFCS
- 2015: CRYPTO
Teaching
TA appointments at ETH Zürich:
- 252-0832-00: Computer Science (Prof. Ralf Sasse and Prof. Malte Schwerhoff) — Spring 2021
- 263-4660-00: Discrete Mathematics (Prof. Ueli Maurer) — Autumn 2020
- 252-0025-01: Applied Cryptography (Prof. Kenneth G. Paterson) — Spring 2020
TA appointments at UC San Diego:
I taught programming to groups of high school students in 2007–2010 and 2012–2013, as a part-time job at Progmeistars.
Miscellaneous
