HQC Beyond the Standard: Ciphertext Compression and Refined DFR Analysis
IACR Eurocrypt
Doctoral Researcher · TU Munich
Sebastian Bitzer
I work on code-based post-quantum cryptography. My work has contributed to CROSS, which reached the second round of NIST's additional signature process, and to recent advances in HQC decoding and DFR analysis.
Research
HQC beyond the standard
Reducing public-key and ciphertext sizes of HQC through generalized concatenated codes and reliability-based errors-and-erasures decoding, with refined decryption-failure-rate analysis.
Restricted decoding & CROSS
Zero-knowledge protocols and signatures from the restricted syndrome decoding problem, underlying the CROSS submission to NIST, with follow-up work on TCitH/VOLEitH-based variants.
Metrics, bounds & decoding
Bounds and codes in the weighted-Hamming, Lee, and cover metrics; information-set decoding with hints and template side-channel attacks on code-based signature schemes.
Publications
2026
2025
2024
2023
2022
→ Earlier work (2019–2020) and complete list available on DBLP and Google Scholar.
Selected Talks
2026
HQC Beyond the Standard: Ciphertext Compression and Refined DFR Analysis
IACR EUROCRYPT, Rome
2025
→ Full talk and poster history on CV (PDF).
Teaching & Supervision
Teaching Assistant
WS 26/27Channel Coding
WS 25/26Channel Coding
WS 24/25Security in Communications and Storage
SS 24Advanced Topics in Communication Systems
SS 23Coding Theory for Storage and Networks
WS 22/23Security in Communications and Storage
WS 20/21Advanced Channel Coding · Uni Ulm
Selected Student Supervision
Master · Erasmus
Zero-Knowledge Protocols based on Restricted Vector Decoding for Post-Quantum Digital Signatures
Master
Decoding Problems via Quantization
with E. Munisamy, S. Ritterhoff
with E. Munisamy, S. Ritterhoff
Master
Improved Solvers for Permutation Equivalence Problems
with A. Porwal
with A. Porwal
Master
Code-Based Homomorphic Encryption for Private Aggregation
with M. Egger
with M. Egger
Master · Erasmus
Improved Restricted Decoding via Nearest Neighbor Techniques
+ 10 further completed internship and thesis projects.
Service
Co-Chair
Munich Workshop on Coding and Cryptography (MWCC) 2024
Three-day workshop at TU Munich (April 2024) with sixteen invited speakers on coding theory, post-quantum cryptography, and privacy-preserving machine learning. Co-organized with R. Bitar, C. Hofmeister, and A. Wachter-Zeh. Workshop webpage →
Reviewer
Conferences
Eurocrypt
2027
Asiacrypt
2023
ISIT
2024
ITW
2024
CBCrypto
2024, 2025, 2026
ISTC
2025
PQCrypto
2026
Journals
IEEE Transactions on Information Theory
2023, 2025, 2026
Advances in Mathematics of Communications
2023, 2024, 2025
Designs, Codes and Cryptography
2025, 2026
Journal of Cryptology
2023
Cryptography and Communications
2025
Computational and Applied Mathematics
2025
IEEE Communications Letters
2025
Contact & Co-Authors
Address
Technical University of MunichAssociate Professorship of
Coding and Cryptography (COD)
Theresienstraße 90, Building N4, Room 3416
80333 Munich, Germany
Mentors
Antonia Wachter-Zeh (advisor)Violetta Weger (mentor)
Part of the CROSS team