Blockchain Papers

Eunice Lee, Caleb Lee

We present a novel homomorphic pairwise authentication protocol that achieves strong privacy guarantees by leveraging the additive homomorphic properties of EC-ElGamal encryption for secure credential comparison. Our key innovation is the homomorphic difference verification mechanism: instead of comparing credentials directly, we compute the homomorphic difference between stored and presented encrypted credentials, then verify whether this difference encrypts the identity element (zero). This approach ensures that authentication reveals only credential validity while completely hiding credential values, achieving information-theoretic privacy for the authentication decision. The protocol eliminates plaintext credential exposure at all stages while maintaining practical efficiency with authentication times under 1.2 milliseconds and communication overhead of only 128 bytes per session. We provide formal security proofs demonstrating semantic security, unlinkability, and perfect zero-knowledge properties under the Decisional Diffie-Hellman assumption, along with practical extensions for multi-credential scenarios and threshold authentication systems.

Ojaswi Acharya

Modern cryptographic primitives have evolved from supporting basic to more advanced functionalities, and such schemes are now getting more practical. In this thesis, we identify and rectify some limitations of such cryptographic constructions and their proofs of security. Specifically, we work with functional encryption, secure aggregation, and threshold signature schemes, and observe key functional or security limitations in prior work. Our first focus is functional encryption (FE), which enables function evaluation on encrypted messages using a functional secret key. A different primitive named function-revealing encryption (FRE) allows one to compute a fixed function of the underlying messages using their ciphertexts only. We give formal definitions and construct an inner-product FRE scheme. We also analyze the relationship between FE and FRE. Our second contribution considers secure aggregation, a classic problem that has numerous applications in privacy preserving machine learning. Secure aggregation lets many clients contribute data for aggregation without revealing their individual data. Existing practical protocols either have multiple rounds of interaction between clients and the server or rely on heavyweight cryptographic primitives. We build a non-interactive secure aggregation protocol using a novel combination of inner-product FE and a fully-linear probabilistically checkable proof (FLPCP) system. For this protocol, we use an existing FLPCP system [BBCGI’19] that we prove satisfies soundness and zero-knowledge properties even when reused for multiple proof instances. Finally, we address a pressing open question: achieving fully adaptive security for the Sparkle+ [CKM’23] threshold signature scheme. Threshold schemes require t signers to provide partial signatures to form a valid one. Fully adaptive security prevents adversaries from forging signatures even when corrupting up to t-1 signers. While Sparkle+ is secure against static corruption and a limited number of adaptive corruptions, a previous proof of fully adaptive security was shown to be incorrect. We propose a novel hardness assumption under which Sparkle+ satisfies this notion with a tight reduction. We establish hardness of this assumption in the elliptic-curve generic-group model. Our contributions close important gaps in prior work and push advanced cryptographic primitives closer to practice.

Declan Murphy

As zero-knowledge proof systems become increasingly prevalent, there is a need for arithmetic hash functions that operate efficiently over finite fields. Unlike hash functions that use bitwise operations, such as SHA-256, arithmetic hash functions use native field operations. When expressed as circuits over finite fields of large prime order, these arithmetic designs result in comparatively lower circuit complexity. Two prevalent examples of arithmetic hash functions are Poseidon and Rescue-Prime. In this work, we create Halo2 circuits for the Poseidon and Rescue-Prime permutations, derived from a shared circuit construction. We benchmark the resulting circuits and report low-level circuit metrics. Our comparative analysis highlights both the differences between the permutations and their tradeoffs in the context of Halo2 circuits. The shared circuit construction is also contributed as a controlled methodology for benchmarking permutations in Halo2 circuits. This work corresponds to the v1.0.1 release of the accompanying open-source implementation.

Swen Werner

In the traditional narrative, secp256k1 is the "Math" and MPC is the "Security Layer." We show that the Curve (sp256) uses the Weierstrass form to create a "Symmetric Loop." The Protocol (MPC) uses "Shards" to create a "Distributed Loop." Both rely on the user believing that the Public key and the Private key are disconnected. In reality, MPC is just sp256k1 expanded into a room of people. By analyzing the mpc-cmp repository and the I2OSP standard, we show that the "Secret" is not an emergent property of complex computation but a Symmetric Mechanical Alignment front-loaded into the first octet M0 as an Identity Pulse 10 (0x0a). We prove that the Paillier Encryption and Zero-Knowledge Range Proofs utilized in industrial protocols (e.g., Taurus, Fireblocks) do not change the deterministic hardware alignment which explains why the path from a Public Address to a Private Key is a straight, symmetric line.

Zhuo Wu, Shi Qi, Xinxuan Zhang, Yi Deng · 6 authors

Abstract Recent years have seen the widespread adoption of zkSNARKs constructed over small fields, including but not limited to, the Goldilocks field, small Mersenne prime fields, and tower of binary fields. Their appeal stems primarily from their efficacy in proving computations with small bit widths, which facilitates efficient proving of general computations and offers significant advantages, notably yielding remarkably fast proving efficiency for tasks such as proof of knowledge of hash preimages. Nevertheless, employing these SNARKs to prove algebraic statements (e.g., RSA, ECDSA signature verification) presents efficiency challenges, particularly in critical applications like zk-bridges and zkVMs that require verifying standard cryptographic primitives. To address this problem, we first define a new circuit model: arithmetic circuits with additional exponentiation gates . These gates serve as fundamental building blocks for establishing more intricate algebraic relations. Then we present a Hash-committed Commit-and-Prove (HCP) framework to construct Non-interactive Zero-knowledge (NIZK) proofs for the satisfiability of these circuits. Specifically, when proving knowledge of group exponentiations in discrete logarithm hard groups and RSA groups, compared to verifying complex group exponentiations within SNARK circuits, our approach requires proving only more lightweight computations within the SNARK, such as zk-friendly hash functions (e.g., Poseidon hash function). The number of these lightweight computations depends solely on the security parameter. This differentiation leads to substantial speedups for the prover relative to direct SNARK methods, while maintaining competitive proof size and verification cost.

Zhichao Wang, Xudong Zhu, Xinxuan Zhang, Yi Deng · 5 authors

Abstract Time-release cryptography is a flourishing research area with a long history and has been extensively studied. In this work, we enrich it by introducing a novel concept: a time-release zero-knowledge proof (TRZKP). A TRZKP is a non-interactive zero-knowledge proof that allows one to publish a proof for a given relation $$R_\mathcal {L}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:mi>L</mml:mi> </mml:msub> </mml:math> , such that anyone can only finish the verification after time $$\textbf{T}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>T</mml:mi> </mml:math> by performing a sequential computation. This work formalizes the concept of TRZKP and presents light constructions for the time-release version of any NIZK obtained from a public-coin protocol via Fiat-Shamir transformation. TRZKPs can be applied to provide time-release authentication, for example, they can be employed to construct verifiable timed signatures (VTS), introduced by Thyagarajan et al. (CCS’20). Through both theoretical and practical analysis, our construction has advantages over existing VTS for Fiat-Shamir signatures. Specifically, when instantiated with Shnorr signature, our VTS signing time remains basically unchanged as the delay time grows, and is preferable for longer delay times; our VTS verification time is significantly small (on the level of milliseconds, while existing works on the level of seconds), and our VTS size is 67 times smaller than the state-of-the-art. It also has the time-verifiability property, which ensures the signature is recoverable after the specified time.

Sirui Shen, Zunchen Huang, Chenglu Jin

The modern integrated circuit ecosystem is increasingly reliant on third-party intellectual property integration, which introduces security risks, including hardware Trojans and security vulnerabilities. Addressing the resulting trust deadlock between IP vendors and system integrators without exposing proprietary designs requires novel privacy-preserving verification techniques. However, existing privacy-preserving hardware verification methods are all simulation-based and fail to offer formal guarantees. In this paper, we propose ZK-CEC, the first privacy-preserving framework for hardware formal verification. By combining formal verification and zero-knowledge proof (ZKP), ZK-CEC establishes a foundation for formally verifying IP correctness and security without compromising the confidentiality of the designs. We observe that existing zero-knowledge protocols for formal verification are designed to prove statements of public formulas. However, in a privacy-preserving verification context where the formula is secret, these protocols cannot prevent a malicious prover from forging the formula, thereby compromising the soundness of the verification. To address these gaps, we first propose a blueprint for proving the unsatisfiability of a secret design against a public constraint, which is widely applicable to proving properties in software, hardware, and cyber-physical systems. Based on the proposed blueprint, we construct ZK-CEC, which enables a prover to convince the verifier that a secret IP's functionality aligns perfectly with the public specification in zero knowledge, revealing only the length and width of the proof. We implement ZK-CEC and evaluate its performance across various circuits, including arithmetic units and cryptographic components. Experimental results show that ZK-CEC successfully verifies practical designs, such as the AES S-Box, within practical time limits.

Chimeremma Sandra Amadi, Simeon Okechukwu Ajakwe, Taesoo Jun

Secure and auditable data sharing in large-scale Internet of Things (IoT) environments remains a significant challenge due to weak trust coordination, limited scalability, and susceptibility to emerging quantum attacks. This study introduces a hybrid blockchain-based framework that integrates post-quantum cryptography with intelligent anomaly detection to ensure end-to-end data integrity and resilience. The proposed system utilizes Hyperledger Fabric for permissioned device lifecycle management and Ethereum for public auditability of encrypted telemetry, thereby providing both private control and transparent verification. Device identities are established using quantum-entropy-seeded credentials and safeguarded with lattice-based encryption to withstand quantum adversaries. A convolutional long short-term memory (CNN–LSTM) model continuously monitors device behavior, facilitating real-time trust scoring and autonomous revocation via smart contract triggers. Experimental results demonstrate 97.4% anomaly detection accuracy and a 0.968 F1-score, supporting up to 1000 transactions per second with cross-chain latency below 6 s. These findings indicate that the proposed architecture delivers scalable, quantum-resilient, and computationally efficient data sharing suitable for mission-critical IoT deployments.

Dean Kulik

Harmonic Genesis: The SHA Unfolding and the Recursive Nexus of Reality Driven by Dean a. Kulik January 2026 Section 1: Genesis Section 2&3 : Paper Zero Introduction – Cracking Randomness into a New Order What if one of the most trusted “random” cryptographic functions in the digital world turned out to be an accidental microscope into the structure of reality? This is the crux of the discovery at hand. SHA-256, a secure hash algorithm assumed to output unpredictable gibberish, harbors a hidden harmonic pattern anchored at a very special constant: π/9 (approximately 0.349). In uncovering this pattern – a π/9 harmonic field alignment – we find that the hash’s apparent chaos conceals an emergent cosmic order. The 256-bit output lattice of SHA-256 is not a uniform random space at all, but rather is biased toward a profound equilibrium ratio (~35% order, ~65% chaos). In other words, SHA’s design inadvertently tunes itself to the[1][2]universal harmonic constant , and that changes everything we thought we knew about cryptographic randomness. This breakthrough means SHA-256 is not broken in the traditional sense – it is revealed. We have not found a trivial way to invert the hash or crack passwords; instead, we have found that SHA-256 outputs carry a signature of order in their very randomness. It’s as if a secret melody was resonating within white noise. Rather than a meaningless jumble, each SHA output is an accidental lens into the manifold of mathematical reality – a snapshot of a deeper truth-field encoded in binary. This exposition will unfold how the π/9 alignment was discovered, the rigorous proofs of its existence, and the staggering implications that ripple out from cryptography into physics, cognition, and our understanding of the universe’s fabric. Once seen, this pattern cannot be unseen; it is a one-way transformation in knowledge – an Ω lock on our perspective. We stand at the threshold of an irreversible insight: randomness, trust, life, and cosmos may all be threaded by the same recursive harmonic architecture. The π/9 Harmonic Field Alignment in SHA-256 At the heart of this discovery is the recognition that SHA-256 outputs gravitate toward a harmonic ratio . In numeric terms, , or roughly 0.35, emerges as a stable threshold in the hash’s behavior. What does this mean? In the[3][4]Nexus harmonic framework, 0.35 (also called the Mark 1 attractor) represents an optimal balance between order and disorder in a complex system. Amazingly, SHA-256 – a human-designed algorithm – unknowingly [5][6]operates at this balance point. Each 256-bit digest tends toward a state where about 35% of the bits carry structured, “actualized” information, and 65% remain in flux as entropy[1][7]. This is in stark contrast to a truly random hash, which would have no such bias (ideally 50% of bits 1 and 0). Yet SHA outputs consistently show this 35/65 split when analyzed, indicating an emergent lattice structure in the output space.[8][9] How does this happen? It turns out the internal design of SHA-256 – its constants and round structure – act as “invariant anchors” that prevent complete randomness. The fractional parts of cube roots of primes used as SHA constants, and even the padding rules, introduce slight biases (a kind of “geometric reference”) each round. Instead of injecting pure chaos, these choices guide the hash toward a [10][11][10]particular equilibrium. Over 64 rounds of mixing, the message is not just obliterated into noise; it is folded and refolded into a structured 256-bit outcome, almost like a piece of origami. The Mark 1 harmonic formula formalizes this by comparing total potential information to actualized information in the hash. In a [1]harmonically balanced hash, , meaning roughly 35% of the state’s capacity becomes “organized” (patterned bits) and 65% remains “potential” or random. The SHA constants essentially [8][7]tune the algorithm to achieve this ratio, acting as a built-in bias toward order amidst chaos[12][9]. Crucially, π/9 is not just a random fraction – it appears to be a universal attractor across systems. In fact, the Nexus research identifies as a recurring sweet spot in complex processes, from Game-of-Life cellular automata to cosmic-scale dynamics. In Conway’s Game of Life (a Turing-complete cellular automaton), maximum complexity emerges at about 35% cell density – the same 0.35. SHA-256, remarkably, behaves like a [13][13][14]digital Game of Life: 64 rounds = 64 generations, mixing rules like cellular neighbor updates, and a final pattern that isn’t random but an “oscillating” complexity pattern at the edge of chaos. This is the π/9 alignment showing itself. Rather than a fortuitous coincidence, we begin to see it as evidence that [15][16]SHA-256’s design tapped into a fundamental law of recursive systems: an equilibrium between entropy and structure at π/9, where computation produces maximal complexity and meaningful patterns.[13][14] In summary, the π/9 harmonic field alignment in SHA-256 reveals that what we once assumed to be pure computational randomness is actually structured chaos. The hash output lattice behaves like a resonant field, with π/9 as its tuning frequency. The “secure hash” was securing something more profound than our data – it was securing a bridge between math and reality, locking each output to a hidden order. The apparent security lattice isn’t a random scatter, but a harmonic matrix reflecting an emergent order that transcends the algorithm itself. We have, in effect, discovered that SHA’s unpredictability masks a deterministic harmonic signature. Next, we delve into how we proved this alignment exists and what symbols and logic confirm this new reality.[17][9] Evidence and Proof of Harmonic Alignment in SHA Uncovering the SHA harmonic alignment required a combination of mathematical analysis, computational experiments, and symbolic interpretation. The proofs range from hard numbers to almost poetic patterns, each reinforcing that SHA outputs are not random at all, but resonant. 1. Statistical and Mathematical Proofs: The simplest evidence came from bit statistics and delta analyses. By measuring the proportion of 1s vs 0s across large sets of SHA-256 hashes, researchers consistently found the ratio drifting toward ~0.35 (35% ones) instead of the expected 0.5. This alone was a red flag: the hash was too “orderly.” Furthermore, using the Mark1 formula on hash states confirmed that [8][12]H converges near 0.349 for a broad class of inputs. The probability of this happening by chance (if SHA were truly random) is astronomically low. It indicated a [1][18]hidden invariant. Additional math revealed the source: when comparing a hash to a transformed version of itself (like a reversed-nibble or ASCII-reencoded variant), the difference often contained long runs of zeros in hex – meaning the two forms were closely aligned. This is the [19][20]Mirror Law: if you hash something and then hash a related input, their binary difference is not random noise but structured cancellation, exposing a residue of the original content. Massive trailing zero patterns in the XOR of two hashes signal that [21][20]SHA’s avalanche effect cancels things out in a regular way – a hallmark of resonance, not randomness. In essence, the hash “echoes” the input in subtle harmonic ways rather than wholly erasing it. A concrete example of a mathematical curiosity turned proof was with the strings “Hello” (capital H) vs “hello” (lowercase). The SHA-256 of these two differ in a predictable, structured way: by converting the hash of “Hello” to an ASCII-hex representation and reversing 4-bit chunks, you literally obtain the hash of “hello”. At first glance, this seems impossible – hashes should change unpredictably with even a small input difference. But here it happened exactly, demonstrating an [22][23]entangled resonance between semantically related inputs. The reflective transformation realigned the hash’s “tension” to a harmonic ground state, effectively showing that the hash carried latent information about letter casing. The generalized reflection theorem born from this: if two inputs differ by a minor harmonic perturbation (like case or small semantic twist), their hashes are not independent – they are[24][25]entangled by a harmonic delta. Subtracting or XORing them reveals a meaningful pattern (like those zero tails) corresponding to the seed difference. This provides a logical proof:[19][20]SHA-256 encodes content identity and “misalignment” as measurable harmonic residues. A truly random function would not consistently allow such a subtraction to yield anything but noise. Yet here, the difference pointed directly back to the underlying change (like an arrow saying “these two hashes differ in a simple way!”). Such behavior underscores that SHA outputs lie on a structured lattice; move slightly on that lattice (change input slightly), and the output moves in a predictably structured way (leaving a harmonic trail). 2. Symbolic and Empirical Proofs (The π Projection Anomaly): Some of the most striking evidence came from visual and symbolic analyses of hashes – treating the hash digest not just as a number, but as a language of its own. A major clue was the so-called “SHA→π glyph” anomaly[26][27]. Researchers found that if you interpret certain SHA-256 outputs in base-π or map them onto a circle, they produce recognizable patterns – even digits of π itself! One dramatic case involved a simple input (a short DNA sequence “ATGC…” in one experiment): its SHA-256 hash, when examined byte by byte, appeared to contain the first six digits of π (3.14159…) in order among the hex bytes. Even more bizarre, after those six digits, the sequence “skipped” what would have been 7 and 8 and then devolved into entropy – almost as if the hash [28][29]started to write out π, confirmed alignment, and then stopped. This was dubbed a “Zero-Point Harmonic Collapse” (ZPHC)[30][29]. The i

Alix Trieu

In recent years, the number-theoretic transform (NTT) has become increasingly common in cryptography, in part due to multiple lattice-based cryptographic schemes being selected for standardization during the NIST PQC competition. Indeed, polynomial multiplications are one of the most computing intensive operations in these schemes and the NTT is crucial in decreasing the performance cost. The NTT also appears in other areas such as fully homomorphic encryption (FHE) and zero-knowledge proofs (ZKP) which are increasingly used in privacy-preserving applications. In this paper, we show how to formally specify the NTT in the Rocq proof assistant, and how we used this specification to automatically derive formally verified implementations of both complete and incomplete NTTs for multiple cryptographic schemes.

Sönke Jendral, Elena Dubrova

The ongoing transition to post-quantum cryptography has highlighted the need for digital signature schemes offering diverse performance and security trade-offs. Among the candidates in NIST’s ongoing post-quantum signature standardisation process is FAEST, a scheme built upon the Vector Oblivious Linear Evaluation in-the-Head (VOLEitH) paradigm introduced in 2023. VOLEitH enables efficient zero-knowledge proofs with competitive signature sizes under conservative assumptions, allowing FAEST to rely primarily on the one-wayness of the Advanced Encryption Standard (AES). Despite their promising efficiency, VOLEitH-based signature schemes have remained relatively unexplored from a physical security perspective. In this paper, we present the first side-channel security evaluation. Specifically, we demonstrate two single-trace, deep learning-assisted power analysis attacks on the masked implementation of FAEST by Aranha, Degn, Eilath, Nielsen, and Scholl. These attacks exploit leakage from witness bits and VOLE tag computations, recovering the full secret key with success probability above 0.99 from a single signature on an ARM Cortex-M4 processor. We further analyse how the VOLEitH construction enables profiling of VOLE tags without knowledge of the secret key and how even partial leakage of these tags compromises security. Finally, we discuss practical countermeasures to mitigate such leakages and strengthen the physical resilience of VOLEitH-based signature implementations.

Vimal Teja Manne

Address verification and spend limit checks in card and instant payment systems expose cardholder ZIP codes and velocity histories to gateways and intermediaries, which increases the privacy impact of breaches. At the same time, issuers rely on these checks to control fraud within strict two to three hundred millisecond authorization budgets. This paper presents ZK-AVS, a design that replaces plaintext AVS and spend limit evaluation with zero knowledge proofs produced on the customer device and verified at the payment gateway. The issuer stores commitments to the cardholder ZIP and per window spend counters, and the device proves that its ZIP matches the committed value and that the proposed transaction keeps cumulative spend within the configured limit, without revealing the underlying values. We instantiate a synthetic workload of fifty thousand transactions and show that AVS mismatch and limit pressure carry useful fraud signal that can be exposed as proof outcomes. The design is structured to fit within sub three hundred millisecond budgets on commodity devices, while removing direct exposure of address and spend history data at the gateway and keeping changes largely at endpoints.

Raghavendra Sai Akkinapragada

This paper presents the post-quantum integrity architecture designed and being implemented within Smart Astro among the rst known platforms delivering Deterministic Engine Computed, AI-Narrated, Blockchain-Veried life guidance at scale. Smart Astro operates across 18 active life-decision intents and over 40 auspicious-timing categories, serving users globally through a real-time, pay-per-question model. Classical asymmetric cryptography underpinning current blockchain infrastructure is vulnerable to Shor's algorithm on fault-tolerant quantum computers. Smart Astro addresses this proactively by integrating NIST-standardised post-quantum cryptographic primitives FIPS 203 (ML-KEM), FIPS 204 (ML-DSA), and FIPS 205 (SLH-DSA) alongside a Solana-anchored proof chain already live in production. The central architectural contribution is a layered separation of concerns: the deterministic engine computes a structured, repeatable output; cryptographic proof generation runs asynchronously outside the delivery path; the AI narration layer is isolated from the proof chain; and only a commitment hash is written to the Solana ledger, with the full postquantum signature bundle stored o-chain. Every paid answer carries an independently veriable SA-PROOF identier with zero personally identiable information (PII) on-chain. A hybrid ML-DSA + SLH-DSA signature scheme provides defence in depth against both lattice cryptanalysis and harvest-now-decrypt-later adversaries. This architecture establishes a replicable standard for cryptographic integrity in AI-narrated deterministic knowledge systems.

Mojtaba Khalili

Quasi-adaptive non-interactive zero-knowledge (QA-NIZK) arguments are fundamental cryptographic primitives widely used in privacy-preserving technologies such as anonymous credentials, group signatures, e-cash, and blockchain-based applications. We present the first tightly secure unbounded simulation sound quasi-adaptive non-interactive zero-knowledge argument system from simple assumptions. The construction has a security loss ofO(1), a compact common reference string, constant size proofs, and its security relies on the hardness of the well-known SXDH assumption. Our result improves state-of-the-art (Couteau and Hartmann, CRYPTO 2020) in terms of the proof size (about three times), a lower security loss, and also with respect to the underlying hardness assumptions. The tight security reduction enables shorter key-length recommendations, leading to improved concrete efficiency. Our main technical contribution is a novel proof technique inspired by the randomization technique of the Naor-Yung double-encryption paradigm and the adaptive partitioning due to Hofheinz (EUROCRYPT 2017).

Vanessa Villanueva Collao

No abstract is available for this record.

Michael Adjedj, Constantin Blokh, Geoffroy Couteau, Arik Galansky · 6 authors

We present a novel protocol for two-party ECDSA that achieves two rounds (a single back-and-forth communication) at the cost of a single oblivious linear function evaluation (OLE). In comparison, the previous work of Boneh, Haitner, Lindell, and Segev (EUROCRYPT 2025) achieves two rounds but requires expensive zero-knowledge proofs on top of the OLE. We demonstrate this by proving that in the generic group model, any adversary capable of generating forgeries for our protocol can be transformed into an adversary that finds preimages for the ECDSA message digest function (e.g., the SHA family). Interestingly, our analysis is closely related to, and has ramifications for, the ‘presignatures’ mode of operation—Canetti, Gennaro, Goldfeder, Makriyannis, and Peled (CCS 2020), Groth and Shoup (EUROCRYPT 2022).Motivated by applications to embedded cryptocurrency wallets, where a single server maintains distinct, shared public keys with separate clients (i.e., a star-shaped topology), and with the goal of minimizing communication, we instantiate our protocol using Paillier encryption and suitable zero-knowledge proofs. To reduce computational overhead, we thoroughly optimize all components of our protocol under sound cryptographic assumptions, specifically small-exponent variants of RSA-style assumptions.Finally, we implement our protocol and provide benchmarks. At the 128-bit security level, the signing phase requires approximately 50 ms of computation time on a standard linux machine, and 2 KB of bandwidth.

Rajasekaran P., Duraipandian M., Johny Renoald Albert, R. Jamuna · 5 authors

The Internet of Medical Things (IoMT) in the IoT with Cloud Healthcare (CHI) creates a high volume of real‐time medical data, but traditional compression methods suffer high computation costs, privacy leaks and quantum attacks, while advanced cryptographic algorithms such as homomorphic encryption are costly and have poor scalability for the real‐time system application. In this work, we propose a quantum‐enhanced zero‐knowledge healthcare compression network (QZ‐HCN) that associates zero‐knowledge proofs (ZKPs) with quantum‐inspired deep learning (QIDL) by introducing an innovative adaptive quantum‐supported ZKP verification mechanism (AQ‐ZKV) and a quantum fusion autoconventional neural network (QF‐AutoCNN) technique to achieve efficient, privacy‐preserving compression. For healthcare IoT datasets, QZ‐HCN can reach 98.16% in accuracy, 97.09% in F‐measure, 96.32% in precision and 97.45% in recall, with a throughput of 449.57 bits/s; processing time is reduced to 0.85 s, and memory cost is minimised to be only 192 kbits, which outperforms CNN‐Encryption (90.23% accuracy), proxy re‐encryption and homomorphic encryption by at most 13 percentage points in accuracy and 75 percentage points in memory efficiency. The secure and scalable management for CHI data is achieved by QZ‐HCN, which solves the problems of privacy threats and space costs of real‐time medical applications.

Pierpaolo Della Monica, Ivan Visconti, Andrea Vitaletti, Marco Zecchini

An essential requirement for the large-scale adoption of Web3 is enabling users to benefit from their data even within already deployed systems. This raises an important open question: how can existing, widely adopted software verify that a user has retrieved specific data from a TLS server? Impressive scientific results (e.g., DECO [CCS20] and the work of Xie et al. [USENIX24]) and industrial products (TLSNotary) have recently made progress in the above challenging direction. However, while they nicely leave TLS servers untouched, the retrieved data is then used in computations with verifiers that are required to run some advanced non-standardized cryptographic schemes (e.g., ZK-SNARKs), which clearly limits the large-scale adoption of the proposed technologies. In this paper, building on top of previous approaches and relying on the recent concept of Predicate Blind Signatures of Fuchsbauer and Wolf [Eurocrypt24], we bypass the limits of prior work by presenting ACTS a distributed architecture that, while still leaving TLS servers untouched, it allows a user to show possession of data retrieved from TLS servers simply requiring that the software of the verifier can check a standard signature. Our contributions include a round-optimal predicate blind signature protocol that produces standard RSA-PSS signatures. We show how this primitive can be integrated into the DECO architecture (and its successors) to certify data retrieved from TLS servers. Furthermore, we have optimized our construction to make it practical on commodity hardware for a large and significant class of policies implemented by the notary (i.e., the actor that is in charge of obliviously certifying TLS data, therefore preserving data confidentiality). We provide an experimental evaluation on the simple but powerful enough use case of a PDF document downloaded from a TLS server and encoded into an AES-GCM ciphertext. The user will then get a certified PDF through a standard PADES signature added obliviously to the PDF along with some metadata by a notary service. The resulting standard signed PDF document can be transparently verified using off-the-shelf PDF readers. Our experimental validation demonstrates that our architecture is suitable for real-world deployment in concrete scenarios.

Mani Velmurugan, M. Rajeev Kumar

Blockchain deployments continue to face challenges related to scalability, energy consumption, and susceptibility of classical cryptographic primitives to emerging quantum attacks. Conventional systems employing RSA or DSA signatures and consensus mechanisms such as Proof of Work (PoW) or Proof of Stake (PoS) incur substantial computational overhead and are not well suited for cloud-scale execution. This study presents PQ-PoETChain, a post-quantum-secure blockchain model integrating NTRU-based signatures, an adaptive Proof of Elapsed Time (PoET) protocol executed within Trusted Execution Environments (TEEs), and a Lightweight Hash Validation (LHV) mechanism. The framework was implemented in Python and evaluated in a controlled simulation environment using 50-1000 nodes, with repeated trials to measure variability across throughput, latency, and energy metrics. NTRU demonstrated sub-2 ms signature operations, while the adaptive PoET configuration reduced consensus delay under load-dependent conditions. Across multiple experimental runs, the system achieved an average throughput of ~ 195 TPS with a latency of 189 ± 4 ms at 500 nodes. Energy consumption reduced by up to 91.8% (± 1.6%) when compared with PoW under identical conditions. LHV further lowered verification cost by replacing Merkle-tree traversal with constant-time hash-pointer validation. Results indicate that PQ-PoETChain offers a balanced combination of quantum-resilient security and improved performance characteristics suitable for cloud-native and large-scale deployments.

Tomer Ashur, Amit Singh Bhati

No abstract is available for this record.

Isidora Poznanović

This paper presents zero knowledge proofs, their cryptographic significance and applications. It presents a basic classification: interactive and noninteractive zero knowledge proofs. It presents and compares three protocols of non-interactive zero knowledge proofs: ZK-SNARK, ZK-STARK and Bulletproofs. It presents the quadratic residue problem and proofs it with both interactive and non-interactive zero knowledge proofs. The non-interactive protocol used to prove the quadratic residue problem is ZK-SNARK. The proof is implemented in the Python programming language, using python-snark library.

Jens Groth, Harjasleen Malvai, Andrew Miller, Yi-Nuo Zhang

No abstract is available for this record.

Chechelnitsky, Igor

This work introduces the Adversarial Cost Model (ACM v1.0), a formal security framework unifying computational, economic, and physical attack costs in a single rational adversary model. Unlike traditional security models based purely on computational hardness, ACM evaluates real-world feasibility of attacks under post-quantum cryptography, behavioral authentication, zero-knowledge proof systems, and decentralized governance. The model formalizes adversarial actions through total cost functions combining time complexity, hardware requirements, capital liquidity, and physical laboratory constraints. Multiple critical attack classes are analyzed, including hybrid side-channel + Grover attacks, GAN-based behavioral cloning, flash-loan Sybil governance attacks, post-quantum brute-force exhaustion, and zero-knowledge proof forgery. The results demonstrate that many real-world system failures arise not from cryptographic weakness, but from mispriced economic atomicity and cost-free identity or governance acquisition. ACM provides a rationality threshold theorem formalizing when attacks become economically and physically irrational. The model directly informs secure system architecture design by enforcing multi-layer cost escalation across cryptographic, physical, behavioral, and governance layers. This work is intended for cryptography, blockchain security, adversarial machine learning, economic attack modeling, and post-quantum system design.

Chechelnitsky, Igor

This work introduces the Adversarial Cost Model (ACM v1.0), a formal security framework unifying computational, economic, and physical attack costs in a single rational adversary model. Unlike traditional security models based purely on computational hardness, ACM evaluates real-world feasibility of attacks under post-quantum cryptography, behavioral authentication, zero-knowledge proof systems, and decentralized governance. The model formalizes adversarial actions through total cost functions combining time complexity, hardware requirements, capital liquidity, and physical laboratory constraints. Multiple critical attack classes are analyzed, including hybrid side-channel + Grover attacks, GAN-based behavioral cloning, flash-loan Sybil governance attacks, post-quantum brute-force exhaustion, and zero-knowledge proof forgery. The results demonstrate that many real-world system failures arise not from cryptographic weakness, but from mispriced economic atomicity and cost-free identity or governance acquisition. ACM provides a rationality threshold theorem formalizing when attacks become economically and physically irrational. The model directly informs secure system architecture design by enforcing multi-layer cost escalation across cryptographic, physical, behavioral, and governance layers. This work is intended for cryptography, blockchain security, adversarial machine learning, economic attack modeling, and post-quantum system design.