Cryptanalysis of the ICCS NGCC Round-1 Public-Key Candidates

Zhenyu Xiong; Mingsheng Wang

Paper 2026/2232

Cryptanalysis of the ICCS NGCC Round-1 Public-Key Candidates

Zhenyu Xiong, Institute of Information Engineering, Chinese Academy of Sciences

Mingsheng Wang, Institute of Information Engineering, Chinese Academy of Sciences

Abstract

The ICCS Next-Generation Commercial Cryptography (NGCC) round-1 call received 84 public-key candidates for public evaluation. We present a design-level assessment that targets weaknesses no local code fix can close, identifying eight such flaws. Each recurs a pitfall already known from NIST PQC standardization: reducible-ring sub-ring projections that break IND-CPA below the claimed level; public data that fixes a value meant to remain secret, enabling public-key-only forgery or keyless decapsulation; static-key reuse without a chosen-ciphertext transform; and rejection sampling whose sign handling leaks an equivalent signing key. All findings were obtained with AI assistance. Artifacts: https://github.com/acprk/ngcc-round1-cryptanalysis.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: post-quantum cryptography cryptanalysis independent verification key recovery IND-CCA decryption-failure oracle
Contact author(s): xiongzhenyu @ iie ac cn
wangmingsheng @ iie ac cn
History: 2026-10-01: last of 3 revisions; 2026-09-27: received; See all versions
Short URL: https://ia.cr/2026/2232
License: CC BY

BibTeX

@misc{cryptoeprint:2026/2232,
      author = {Zhenyu Xiong and Mingsheng Wang},
      title = {Cryptanalysis of the {ICCS} {NGCC} Round-1 Public-Key Candidates},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/2232},
      year = {2026},
      url = {https://eprint.iacr.org/2026/2232}
}