christian janson

I am a Postdoc in the Cryptoplexity team led by Marc Fischlin at Technische Universität Darmstadt. Prior to this I was a Ph.D. student in the Information Security Group at Royal Holloway, University of London under the supervision of Carlos Cid. It all began at Universität Bremen where I studied mathematics and completed my diploma in the AlZAGK group under the supervision of Michael Hortmann.

I am a member of the IACR and my Erdös-Bacon number is 6.

research interests

My main (current) research interests are:

  • key exchange

  • authenticated encryption

  • secure channels

  • signature schemes


19.09.2020: Our paper Towards Post-Quantum Security for Signal's X3DH Handshake (joint work with Jacqueline Brendel, Marc Fischlin, Felix Günther and Douglas Stebila) has been accepted to SAC 2020

16.08.2020: Our paper Security Reductions for White-Box Key-Storage in Mobile Payments (joint work with Estuardo Alpirez Bock, Chris Brzuska, Marc Fischlin and Wil Michiels) has been accepted to ASIACRYPT 2020

23.06.2020: Our paper Client-oblivious OPRAM (joint work with Gareth T. Davies and Daniel P. Martin) has been accepted to ICICS 2020

15.06.2020: Our paper Robust Channels: Handling Unreliable Networks in the Record Layers of QUIC and DTLS 1.3 (joint work with Marc Fischlin and Felix Günther) is now available on ePrint. Our results informed the IETF QUIC and TLS working groups, contributing forgery limits to the upcoming standards for QUIC and DTLS 1.3.

academic career and education

since July 2016: Postdoctoral researcher in the Cryptoplexity team, Technische Universität Darmstadt

2012-2016: Ph.D. in Information Security, Royal Holloway, University of London

2006-2012: Diploma in mathematics, Universität Bremen

professional activities

May 2019: Eurocrypt 2019 Workshop General Co-Chair

since March 2017: member of examining board (Prüfungskommission) in the computer science department

peer reviewing

Scientific Conferences

2020: PKC, Crypto

2019: PKC, Crypto, Asiacrypt, IMA CC

2018: Financial Cryptography, PKC, CT-RSA, Crypto, CCS, iPAT, Asiacrypt


2016: CT-RSA


2014: SAC


2017: Journal of Designs, Codes and Cryptography

2016: Journal of Designs, Codes and Cryptography, IEEE Transactions on Information Forensics and Security

programm committee

2020: iPAT

2019: IMA CC, iPAT

2018: iPAT


2018: Best Teaching Award for Lecture Real World Crypto, TU Darmstadt, summer term 2017 (teaching assistant)

research visits

January 2019: UCSD, San Diego, USA - Dep. of Computer Science and Engineering

Host: Dr. Felix Günther

September 2017: NTNU Trondheim, Trondheim, NO - Dep. of Information Security and Communication Technology

Host: Prof. Colin Boyd & Dr. Gareth T. Davies

August 2015: Universität Mannheim, Mannheim, GER - Dependable Systems Engineering

Host: Prof. Dr. Frederik Armknecht

Mai 2015: Universität Mannheim, Mannheim, GER - Dependable Systems Engineering

Host: Prof. Dr. Frederik Armknecht



Rune Fiedler (November 2019-May 2020) - Stronger Security Notions for Post-Quantum Signature Schemes (co-supervised with Marc Fischlin)

Oliver Käfer (ongoing) - Formale Verifikation von Bluetooth (co-supervised with Marc Fischlin)


Timo Klonowski (May-July 2019) - Sicherheit des USB-Typ-C Authentifizierungsprotokolls (co-supervised with Marc Fischlin)

Jean-Pierre Münch (April-July 2019) - Analysis of the Current State of Non Memory-hard Password-based Cryptographic Primitives (co-supervised with Marc Fischlin)