Quantum Composable and Contextual Security  Infrastructure (Q2CSI) : A Modular Architecture for  Legally Explainable Cryptographic Signatures

Thierry Emmanuel MINKA MI NGUIDJOI; MANI ONANA Flavien Serge; DJOTIO NDIÉ Thomas; BOUETOU BOUETOU Thomas

Paper 2025/1380

Quantum Composable and Contextual Security Infrastructure (Q2CSI) : A Modular Architecture for Legally Explainable Cryptographic Signatures

Thierry Emmanuel MINKA MI NGUIDJOI

, Laboratory of Mathematical Engineering and Information Systems (LIMSI), National Advanced School of Engineering, University of Yaoundé I, Cameroon

MANI ONANA Flavien Serge, Laboratory of Mathematical Engineering and Information Systems (LIMSI), National Advanced School of Engineering, University of Yaoundé I, Cameroon

DJOTIO NDIÉ Thomas, Laboratory of Mathematical Engineering and Information Systems (LIMSI), National Advanced School of Engineering, University of Yaoundé I, Cameroon

BOUETOU BOUETOU Thomas, BOUETOU BOUETOU Thomas

Abstract

The fundamental incompatibility between confidentiality, reliability, and le gal opposability, formalized as the CRO trilemma, imposes an entropic bound Γ_CRO on cryptographic security in contextual adversarial settings. This pa per introduces Q2CSI (Quantum Composable Contextual Security Infras tructure), a layered framework resolving this trilemma through dialectical separation. Q2CSI decomposes security guarantees into three isolated yet composable layers: Iron (reliability: temporal/logging integrity), Gold (con f identiality: semantic entropy preservation), and Clay (opposability: insti tutional interpretability). By embedding entropic constraints into an ex tended Universal Composability (UC) model, Q2CSI achieves Γ_CRO < 0.4, surpassing monolithic designs, while maintaining post-quantum resilience. The architecture is abstractly instantiated with minimal primitives (IND CCA2 encryption, EUF-CMA signatures) and validated via a symbolic UC framework. Proofs demonstrate strict dialectical isolation, bounded contex tual leakage, and compatibility with quantum adversaries. Q2CSI establishes a foundation for legally verifiable post-quantum protocols, with applications in zero-knowledge attestations and regulatory-compliant signatures.

Note: This manuscript is part of a structured research program on the legal explainability of post-quantum cryptographic protocols. It formalizes a generic composable infrastructure (Q2CSI) built upon the CRO Trilemma (ePrint 2025/1348) and offers an abstract model suitable for multiple instantiations. One such instantiation, based on concrete cryptographic primitives, has been presented in ePrint 2025/1138. The present submission does not include implementation artefacts and makes no performance claims. It focuses exclusively on the theoretical and formal aspects of protocol design and composability. All contributions are original. This manuscript is not under submission or review elsewhere. The author may reference this ePrint in future related works (e.g., instantiations or applied extensions), without redundancy or duplication of content.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint.
Keywords: CRO Trilemma Post-Quantum UC Security Contextual Signatures Composable Protocols Legal Opposability
Contact author(s): minkathierry @ gmail com
serge mani @ digitworldacademy com
tdjotio @ gmail com
tbouetou @ gmail com
History: 2025-07-30: approved; 2025-07-29: received; See all versions
Short URL: https://ia.cr/2025/1380
License: CC BY

BibTeX

@misc{cryptoeprint:2025/1380,
      author = {Thierry Emmanuel MINKA MI NGUIDJOI and MANI ONANA Flavien Serge and DJOTIO NDIÉ Thomas and BOUETOU BOUETOU Thomas},
      title = {Quantum Composable and Contextual Security  Infrastructure ({Q2CSI}) : A Modular Architecture for  Legally Explainable Cryptographic Signatures},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1380},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1380}
}