arXiv subjects

Victor Duarte Melo

Publications and source records attributed to Victor Duarte Melo.

6 recordsLinked to original sources

arXiv2026

FrogBard-512: Design and Experimental Evaluation of a Four-Voice Permutation-Based Hash Function

FrogBard-512 is an experimental 512-bit hash function based on a custom 2048-bit permutation organized as four 512-bit voices. The sequential mode uses a 1024-bit rate, a 1024-bit capacity, 128-byte message blocks, and a 16-round permutation. Each round combines public round constants, four AES-derived affine-equivalent byte substitutions, ARX quarter-rounds, a parity-dependent cross-voice mixing layer, and fixed lane permutations. The design also includes a separately domain-separated tree mode with 1 MiB leaves, multithreaded processing, and an AVX2 backend for four independent equal-length messages. This paper gives a self-contained description of the construction, constant generation, padding, finalization, tree encoding, implementation profiles, and conformance vectors. It also reports an experimental evaluation covering fixed-vector tests, streaming equivalence, permutation inversion, scalar and SIMD agreement, sanitizer runs, Valgrind-based memory and race analysis, randomized API testing, libFuzzer, AFL++, reduced-round diffusion measurements, and large-stream statistical testing with PractRand and Dieharder. The reported results provide evidence of implementation consistency and the absence of obvious statistical defects in the tested configurations. They do not establish collision resistance, preimage resistance, indifferentiability, or structural security. FrogBard-512 remains a research prototype and has not undergone independent cryptanalysis.

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arXiv2026

Exact Hidden Paths in Noisy High Dimensional Path Spaces

We introduce a mathematical and cryptographic framework for exact recovery of noisy hidden paths in high dimensional discrete path spaces. The work is inspired by the path integral viewpoint, where global quantities arise from contributions over many possible trajectories. Instead of approximating a global path sum, we study the inverse problem of recovering one exact hidden trajectory from incomplete, noisy, projected, and aggregated observables. The hidden object is a planted discrete path whose transitions may include macro steps, microscopic perturbations, and discrete noise. Public information is represented by large observable vectors rather than short hash digests, since excessive compression would bound the effective recovery problem by the digest size. We formalize several recovery notions, including planted exact recovery, arbitrary witness recovery, canonical recovery, quotient recovery, and recovery of derived encodings. The main distinction is that approximate reconstruction and exact recovery are fundamentally different tasks. A method may reveal coarse geometry or dominant regions without recovering the precise microscopic sequence defining the hidden path. We also discuss attack surfaces relevant to future cryptographic use, including linearization, lattice style recovery, dynamic programming, meet in the middle attacks, SAT and SMT formulations, approximation followed by rounding, witness collisions, and generic quantum search. This work does not claim a complete post quantum cryptosystem. It provides a formal framework for studying exact hidden path recovery as a possible foundation for future cryptographic constructions

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arXiv2026

ECCFROG522PP: An Enhanced 522 bit Weierstrass Elliptic Curve

This paper presents ECCFROG522PP, a 522-bit prime-field elliptic curve in short Weierstrass form, designed with a focus on deterministic generation and public reproducibility. The central design principle is that all critical parameters are derived from a fixed public seed through a transparent and verifiable procedure. While many deployed systems rely on NIST P-256 and secp256k1, which target approximately 128-bit classical security, higher security applications typically consider curves such as NIST P-521, Curve448, and Brainpool P512. ECCFROG522PP is intended for the same general classical security range as P-521, with emphasis on transparency, auditability, and reproducibility rather than performance optimization. The curve parameters are generated through a BLAKE3-based deterministic pipeline with publicly specified indices. The resulting construction has prime order, cofactor one, and a deterministically derived base point of full order. The quadratic twist has a large proven prime factor, and the construction includes a documented lower bound on the embedding degree together with standard sanity checks against low embedding degree reductions and basic CM discriminant anomalies. The full generation and validation procedure can be reproduced end to end from public artifacts and reference scripts, enabling independent verification of all parameters and checks.

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arXiv2026

The HyperFrog Cryptosystem: High-Genus Voxel Topology as a Trapdoor for Post-Quantum KEMs

HyperFrog is an experimental post-quantum Key Encapsulation Mechanism that explores a variant of the Learning With Errors (LWE) design space in which the secret is not sampled from an independent product distribution, but is deterministically derived from discrete topological structure. The scheme embeds a voxel grid in three dimensions and uses a topology mining procedure to search for connected subgraphs with prescribed complexity, measured by cyclomatic number (high genus). The resulting structure is encoded as a sparse binary secret vector, inducing strong geometric constraints on the secret distribution while retaining a large combinatorial search space. Encapsulation produces noisy linear relations over public parameters and derives the shared key via hashing; a Fujisaki-Okamoto style transform is used to target IND-CCA security in the random oracle model. We present the construction, parameterization, and serialization format, together with a reference implementation featuring self-tests and benchmarking on commodity CPUs. We also discuss how topology-derived secrets interact with known lattice and decoding attacks, and we outline open problems required for conservative parameter selection and for a full security analysis. HyperFrog is intended as a research vehicle rather than a production-ready KEM.

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arXiv2026

Symfrog-512: High-Capacity Sponge-Based AEAD Cipher (1024-bit State)

This submission includes a complete reference implementation together with deterministic test vectors and a reproducible benchmark suite. All source code, build instructions, and regression artifacts are publicly available in the project repository, enabling independent verification and reimplementation of the scheme. The AEAD construction is fully specified, including domain separation, rate and capacity choices, tag generation, and the exact file format used by the reference CLI. Reported performance numbers are produced by the built in benchmark tool under documented hardware and compiler settings. All security claims are made strictly within the ideal permutation model following standard sponge and duplex bounds, and no stronger guarantees are asserted for the concrete permutation beyond the documented analysis and empirical behavior. The implementation aims for constant time behavior with respect to secret dependent operations, although no formal side channel proof is provided. The project is released under the MIT license, and external cryptanalysis, feedback, and reproducibility checks are explicitly encouraged.

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arXiv2025

KyFrog: A High-Security LWE-Based KEM Inspired by ML-KEM

KyFrog is a conservative Learning-with-Errors (LWE) key-encapsulation mechanism designed to explore an alternative operating point compared to schemes with relatively small public keys and ciphertexts. KyFrog uses a larger dimension ($n = 1024$) and a small prime modulus $q = 1103$, together with narrow error distributions with standard deviations $σ_s = σ_e = 1.4$, to target approximately $2^{325}$ classical and quantum security against state-of-the-art lattice attacks under standard cost models, as estimated using the Lattice Estimator. The price paid for this security margin is an extremely large KEM ciphertext (about 0.5 MiB), while public and secret keys remain in the same ballpark as ML-KEM. We describe the design rationale, parameter search methodology, and implementation details of KyFrog, and we compare its asymptotic security and concrete parameter sizes with the ML-KEM standard. All code and data for this work are released as free and open-source software, with the full C++23 implementation and experimental scripts available at: https://github.com/victormeloasm/kyfrog

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