The Fischlin transform yields non-interactive zero-knowledge proofs with straight-line extractability in the classical random oracle model. This is done by forcing a prover to generate multiple accepting transcripts through a proof-of-work mechanism. Whether the Fischlin transform is straight-line extractable against quantum adversaries has remained open due to the difficulty of reasoning about the likelihood of query transcripts in the quantum-accessible random oracle model (QROM), even when using the compressed oracle methodology. In this work, we prove that the Fischlin transform remains straight-line extractable in the QROM, via an extractor based on the compressed oracle. This establishes the post-quantum security of the Fischlin transform, providing a post-quantum straight-line extractable NIZK alternative to Pass' transform with smaller proof size. Our techniques include tail bounds for sums of independent random variables and for martingales as well as symmetrization, query amplitude and quantum union bound arguments.
Arka Pal, Louai Zahran, William Gvozdjak, Akilesh Potti · 5 authors
As large language models (LLMs) continue to grow in size, fewer users are able to host and run models locally. This has led to increased use of third-party hosting services. However, in this setting, there is a lack of guarantees on the computation performed by the inference provider. For example, a dishonest provider may replace an expensive large model with a cheaper-to-run weaker model and return the results from the weaker model to the user. Existing tools to verify inference typically rely on methods from cryptography such as zero-knowledge proofs (ZKPs), but these add significant computational overhead, and remain infeasible for use for large models. In this work, we develop a new insight -- that given a method for performing private LLM inference, one can obtain forms of verified inference at marginal extra cost. Specifically, we propose two new protocols which leverage privacy-preserving LLM inference in order to provide guarantees over the inference that was carried out. Our approaches are cheap, requiring the addition of a few extra tokens of computation, and have little to no downstream impact. As the fastest privacy-preserving inference methods are typically faster than ZK methods, the proposed protocols also improve verification runtime. Our work provides novel insights into the connections between privacy and verifiability in LLM inference.
Introduction In the contemporary digital health landscape, securing personal health data against unauthorized access while ensuring its verifiability is a paramount challenge. A critical conflict exists between the transparency required for data verification and the privacy mandated by global regulations such as HIPAA and GDPR. Existing Layer-1 blockchain solutions suffer from prohibitive gas costs and high latency, rendering them unsuitable for real-time monitoring of high-volume health data streams. Methods This paper proposes TeleZK-L2, a novel framework that synergizes distributed Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge (zk-SNARKs) with Layer-2 scaling solutions. The architecture introduces a Distributed Prover Network (DPN) to parallelize heavy cryptographic computations and utilizes Optimistic Proof Aggregation to minimize on-chain data footprints. The verification logic is anchored on the Polygon zkEVM to ensure high throughput and low-cost settlement. Results Extensive simulations on a 16-node high-performance cluster demonstrate that TeleZK-L2 generates proofs at a rate 40% faster than the standard Groth16 baseline. Furthermore, the framework reduces on-chain verification costs by approximately 52%. The system maintains constant-time verification complexity regardless of batch size, achieving a peak throughput of 260 TPS. Discussion TeleZK-L2 provides the technical privacy guarantees necessary to support adherence to HIPAA and GDPR data minimization mandates while maintaining cryptographic soundness. By resolving the "Scalability-Privacy Trilemma," this framework demonstrates significant potential for large-scale deployment in national telehealth infrastructures and remote patient monitoring ecosystems.
We study the implications of the existence of weak Zero-Knowledge (ZK) protocols for worst-case hard languages. These are protocols that have completeness, soundness, and zero-knowledge errors (denoted $ε_c$, $ε_s$, and $ε_z$, respectively) that might not be negligible. Under the assumption that there are worst-case hard languages in NP, we show the following: 1. If all languages in NP have NIZK proofs or arguments satisfying $ ε_c+ε_s+ ε_z < 1 $, then One-Way Functions (OWFs) exist. This covers all possible non-trivial values for these error rates. It additionally implies that if all languages in NP have such NIZK proofs and $ε_c$ is negligible, then they also have NIZK proofs where all errors are negligible. Previously, these results were known under the more restrictive condition $ ε_c+\sqrt{ε_s}+ε_z < 1 $ [Chakraborty et al., CRYPTO 2025]. 2. If all languages in NP have $k$-round public-coin ZK proofs or arguments satisfying $ ε_c+ε_s+(2k-1).ε_z < 1 $, then OWFs exist. 3. If, for some constant $k$, all languages in NP have $k$-round public-coin ZK proofs or arguments satisfying $ ε_c+ε_s+k.ε_z < 1 $, then infinitely-often OWFs exist.
Eman Alatawi, Anoud Alhawiti, Doaa Albalawi, Umar Albalawi
The rapid expansion of the Internet of Things (IoT) has led to billions of interconnected devices generating and exchanging sensitive data across diverse domains, which introduces challenges in identity management (IdM) regarding privacy, scalability, and verifiability. While blockchain technology provides decentralization and tamper resistance, its transparency and increasing on-chain storage demands make it unsuitable for large-scale IoT identity ecosystems. To overcome these challenges, IoT-SBIdM is proposed as a lightweight, privacy-preserving, and stateless blockchain-based identity management framework designed for IoT environments. This framework incorporates Elliptic Curve Cryptography (ECC)-based accumulators and Zero-Knowledge Proofs (ZKPs) to facilitate selective disclosure, enabling entities to prove credential authenticity without exposing sensitive identity information. Furthermore, the framework adopts W3C-compliant Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs) to promote interoperability and user-controlled identity ownership. The experimental results indicate that IoT-SBIdM achieves efficient smart contract execution by reducing gas costs through optimized registry logic. Moreover, the system maintains a compact block size of only 45 MB at higher block heights, outperforming comparable schemes in storage efficiency by achieving a 55% reduction relative to recent models and an approximate 94% reduction relative to older systems, thereby demonstrating superior scalability and storage efficiency, making it suitable for identity management solutions for IoT environments.
Zibin Lin, Taotao Wang, Shengli Zhang, Long Shi · 6 authors
Web 3.0 platforms need an onboarding mechanism that can admit real users at scale without forcing them to reveal identity documents or pay one on-chain verification cost per user. Existing approaches typically rely on KYC-style disclosure, per-request on-chain verification, or trusted batching, making onboarding cost and latency difficult to predict under bursty demand. We present \textbf{ZK-AMS}, a credibly anonymous admission infrastructure that maps Personhood Credentials to anonymous on-chain Soul Accounts. Rather than introducing a new primitive, ZK-AMS composes zero-knowledge credential validation, permissionless batch submission, recursive proof aggregation, and anonymous post-admission account provisioning into one end-to-end workflow. Its key design feature is a confidential batching pipeline in which admission instances of a common relation are folded off-chain under multi-key homomorphic encryption, allowing an untrusted batch submitter to coordinate aggregation without direct access to individual user witnesses during batching; the confidentiality scope is characterized explicitly in the security analysis. The resulting batch is settled on-chain with constant verification cost per batch rather than per admitted user. We implement ZK-AMS on an Ethereum testbed and evaluate admission throughput, end-to-end latency, gas consumption, and parameter trade-offs. Results show stable batch-verification gas across evaluated batch sizes, substantially lower amortized on-chain cost than the non-recursive baseline, and practical cost-latency trade-offs for high-concurrency onboarding in Web 3.0 platforms.
Atefeh Nekouie, Majid Vafaei Jahan, Mohammad Hossein Moattar, Reza Sheibani
Access control and data privacy are two of the main necessities in managing electronic health records (EHRs) across distributed domain. There are privacy gaps that expose EHRs to risks like unauthorized access by unaffiliated medical personnel. Traditional attribute-based encryption (ABE) allows encryption based on user attributes but is unable to incorporate data-specific attributes, such as the type of medical information included in the record or the potential physician. This paper introduces a novel approach that integrates ABE with large language models (LLMs) and blockchain technology to enhance security and contextual access control in EHR systems. Specifically, a domain-specific LLM, such as ClinicalBERT, is leveraged to automatically extract semantic data attributes from unstructured medical records, enabling a more granular and context-aware encryption process. By embedding both user and data attributes into the ABE framework, access policies are dynamically refined, ensuring that only authorized users can view specific types of medical information. Furthermore, blockchain's immutable ledger enhances trust, streamlines attribute revocation, and fortifies the system against unauthorized modifications and security threats. The proposed framework significantly strengthens EHR privacy by integrating machine learning-driven attribute extraction with cryptographic access control, outperforming existing schemes in both security and flexibility. Evaluations validate the effectiveness of the proposed framework in preventing unauthorized access while maintaining efficient and transparent data management.
Michele Battagliola, Laura Mattiuz, Alessio Meneghetti
Abstract The Vector Oblivious Linear Evaluation in the Head (VOLEitH) paradigm has proven to be a versatile tool to design zero-knowledge proofs and signatures in post-quantum cryptography. In this paper, we propose three VOLE-friendly modellings for Proofs of Knowledge (PoK) of a solution of an instance of the Linear Code Equivalence Problem (LEP). For the first two schemes, we propose two new reductions from LEP to the Multivariate Quadratic (MQ) problem, that may be of independent interest for the cryptanalysis of LEP. Instead, the last model is obtained by generalizing a recent work by Bettaieb et al. to the context of monomial matrices instead of permutation matrices. While our proposed schemes exhibit larger signature sizes compared to LESS, they improve the computational efficiency, reducing the overall complexity from $$O(n^3)$$ to $$O(n^2\log n )$$ and $$O(n^2\log ^2 n )$$ , where n is the length of the code.
Everything is becoming digital these days, health records are no exception. Digitization of healthcare sector would make the outcome improved such as enhanced patient care, but like every digitization, this has also introduced significant privacy and security concerns such as health data breaches. This paper proposes a “Health-ID Verification Framework” that combines blockchain, ECDSA and ZKPs to enable secure, GDPR-compliant health id verification. zk-ID leverages zk-SNARKS for privacy preservation, chameleon hashes are used for retroactive redaction that is in line with GDPR’s “right to be forgotten” clause. Sharded Blockchain networks achieve about 1,200 TPS. Evaluations show zk-ID reduces verification latency by 62% compared to Sovrin and lowers storage costs to 21.67/record via hybrid on/off-chain architectures. Interoperability is achieved through FHIR/HL7 APIs while eliminating fraud through multi-authority attribute-based encryption (MA-ABE).
Disentangle introduces Topological Mass Consensus (TMC), a permissionless consensus mechanism that derives Sybil resistance from discrete curvature on transaction DAGs rather than proof-of-work or proof-of-stake. Edges connecting attack clusters to the honest network exhibit negative Jaccard curvature due to low ancestor overlap, enabling geometric throttling without trusted seeds or economic incentives. The protocol uses exclusively post-quantum cryptography (ML-DSA, ML-KEM, SHA3-256, Plonky3 STARKs) and derives all temporal properties from topological depth. We also present the Capability-Coherence Identity Protocol (CCIP), unifying DID-based identity, object capabilities, and petname naming under the same curvature analysis. Implementation: 9 Rust crates, 349+ tests.
Ms. Neha Beegam P E, Mr. Alen K Sangeeth, Mr. Athulraj Appukuttan, Mr. Alex Jo Tomy · 5 authors
With the rapid digital transformation of ed- ucational and professional environments, certificate ver- ification has become a critical security concern. Tra- ditional certificate authentication systems rely on cen- tralized repositories and manual verification processes, which are vulnerable to forgery, unauthorized modifica- tion, and operational inefficiencies. Blockchain technol- ogy offers a decentralized, immutable, and transparent framework that addresses these challenges. This sur- vey presents an extensive review of blockchain-based cer- tificate authentication systems proposed in recent litera- ture. Various architectures, blockchain platforms, smart contract models, cryptographic mechanisms, and opti- mization techniques are analyzed. A detailed compari- son is presented to highlight strengths, limitations, and open research challenges. The study aims to serve as a comprehensive reference for researchers and practition- ers working on secure and scalable certificate verifica- tion solutions.
Secure and private sharing of electronic health records (EHRs) among multiple parties remains a significant challenge in digital healthcare. Although Blockchain technology can ensure data integrity through security and transparency, protecting patient privacy and enabling secure collaborative analysis continue to be difficult problems. To address these challenges, differential privacy (DP) and Zero-Knowledge Proofs (ZKPs) are integrated into a Blockchain-based solution in the innovative design of this multi-institutional EHR-sharing system architecture. ZKPs enable the verification of user identities and access requests without revealing sensitive information, while DP ensures that analytical results are statistically valid and that underlying data are protected against re-identification attacks. A permissioned Blockchain system is developed to support verifiable and privacy-preserving federated analytics over distributed data. Experimental results demonstrate that the proposed framework successfully achieves privacy protection, secure access, and interoperable data-sharing objectives.
Digitization of healthcare has provided opportunities for improving patient care but also has brought with it major security vulnerabilities that could compromise the confidentiality, availability, and integrity of protected health information. This article reviews the proposed distributed system constructs for providing health data security between heterogeneous systems, organizations, and multiple institutions. It categorizes and reviews three approaches to distributed healthcare security: (1) Advanced Encryption Algorithms, including symmetric, asymmetric and homomorphic algorithms for encrypting health information-at-rest and in-transit, and key management mechanisms for secure access to cryptographic material across multiple nodes that may not be trusted; (2) Distributed Storage Systems, including distributed-ledger technology (DLT), distributed file systems, and fragmentation approaches for immutable patient consent and audit trail logging, redundancy to tolerate physical node compromise, and avoiding total infrastructure data loss due to localized security attacks; and (3) Access Control Mechanisms, including multi-factor authentication, role-based access control, attribute-based access control, federated identity management for distributed healthcare organizations, and patient access control and monitoring for distributed threat detection. The distributed model is now more attractive in modern health systems. Perimeter security models do not adequately protect health data. The health data moves through networks connecting hospitals, outpatient clinics, clinical research organizations, insurance companies, and third-party organizations. The proposed framework satisfies regulations according to HIPAA, the General Data Protection Regulation (GDPR), and the Health Information Technology for Economic and Clinical Health (HITECH) Act. The system can be performance optimized to balance between cryptographic strength and system responsiveness. The combination of encryption, decentralized storage, and access control provides defense-in-depth protection against cyberattacks. Future developments, such as artificial intelligence-enabled threat detection, quantum-resistant cryptographic algorithms and models for patient data control will shape how to create secure healthcare systems in our growing digital health networks.
The lattice-based encryption is one of the most appropriate choices to secure the blockchain technology during the post-quantum era withstanding security against a quantum adversary attack. The authors study lattice-based cryptography and integrate it with the blockchain architecture in order to address gaps that have recently been exposed because of the continued advances with quantum systems. However, a majority of the classical cryptographic designs such as RSA and ECC are designed around the difficulty of particular mathematical problems, one of which is the Shor algorithm, which makes them highly susceptible to quantum algorithms. Learning with Errors (LWE) and Short Integer Solution (SIS). The paper will discuss the feasibility of lattice-based digital signatures, zero-knowledge proofs, and encryption systems that should be deployed in blockchain so that the integrity of data should be maintained, transactions should be secure, and privacy of users should be preserved. Furthermore, it introduces performance features of blockchain where it considers the lattice-based cryptographic systems where it entails scalability, complexity of computing, and latency. The results are then employed to support the options of encryption with lattices to lay the groundwork for the architecture to quantum-resistant blockchain-based frameworks, and the ultimate stage of secure and scalable decentralized networks in the post-quantum world.
Blockchain technology, characterized by its immutable, distributed ledger, has evolved significantly beyond its cryptocurrency origins, finding application in healthcare and organ donation systems. Specifically, Hyperledger Fabric emerges as a secure, enterprise grade solution for healthcare data management, with a primary focus on patient medical records. Traditional centralized storage of medical records poses challenges for patients, prompting the development of a Hyperledger Fabric-based system driven by smart contracts to enhance accessibility and security. In the realm of organ donation systems, blockchain is proposed as a remedy for the shortcomings of centralized models, offering heightened transparency and security. Notably, while previous solutions often leaned on Ethereum-based blockchains, this research pioneers the use of Hyperledger Fabric. Beyond organ donation, blockchain's attributes, including decentralization, transparency, and privacy, offer transformative potential in healthcare.
Raman Chadha, Paras Mahajan, Rajat Gupta, Sunil Khullar
The centralized nature of the existing digital identity infrastructure provides single points of failure and potential breaches of user privacy. This work proposes a decentralized infrastructure for managing digital identities using a permissioned blockchain and W3C-compliant Decentralized Identifiers and Verifiable Credentials together with zero-knowledge proofs to support a user-controlled and privacy-preserving identity verification process. The experiment verifies the ability of the proposed infrastructure to handle up to 155 transactions in the verification process in 105 ms for a maximum of 500,000 users without the possibility of egress operations as a potential threat to perform unauthorized access to the personal user information. User test participants are satisfied with the design of the wallet interface and the management of the corresponding consents. Process analysis indicates the feasibility of the designed infrastructure in complying with the key principles of the GDPR and CCPA regulations.
The rapid expansion of the blockchain gaming sector, projected to reach a $268.8 billion valuation by 2025 1 , has been severely compromised by the proliferation of automated Sybil attacks and bot-driven economic manipulation. Traditional anti-bot measures, such as CAPTCHAs and behavioural analytics, are increasingly circumvented by advanced AI-driven scripts. This paper proposes a novel Context-Aware Reputation-Identity Hybrid (CRIH) framework that integrates biometric-backed Proof-of-Personhood (PoP) with decentralized reputation metrics. By leveraging World ID’s hardware-oracle verification and recursive Zero-Knowledge Proofs (ZKPs), the CRIH framework enables thrustless identity portability across Layer 2 (World Chain) and Layer 3 (Mythos Chain) architectures. We demonstrate that this tiered, risk-sensitive approach significantly reduces bot-driven inflation while preserving player privacy and minimizing onboarding friction.
In order to ensure the transparent and immutable maintenance of healthcare data, Blockchain technology has been proposed, but it places privacy against core requirements—one of which is privacy demanded by law. Anonymization techniques present today are useful in providing privacy, however they fall short in this sense in terms of guarantee. While zero-knowledge proofs (ZKPs) are one of the strongest cryptographic attestations, they come with hefty computational costs. This paper proposes an HH-ZKP model within a patient-specific-scope and selective disclosure on a smart contract. On a preliminary note, energetic sorting of electronic health records is actually done where anonymization is achieved using hybrid heuristic methods adhering to the constraints of k-anonymity and l-diversity. This is later followed by succinct ZKPs, ensuring that privacy is being obeyed without exposure of any of the hiding values. Again, the aggregations of these proofs are put onto the block with the smart contract, optimized for gas usage, to increase the scalability to a higher level. It is shown through experimental evaluations on the 10 K synthetic EHR dataset that the proposed scheme shows about a 75% reduced on-chain cost four times reduced proof sizes fully meeting HIPAA Safe Harbor compliance. The HH-ZKP model, by yielding a hybrid of heuristic-preprocessing and formal-principled cryptographic verification, is paving the way for scalable and regulator-aware blockchain health applications.
Guilhem Repetto, Nojan Sheybani, Gabrielle De Micheli, Farinaz Koushanfar
Privacy concerns in machine learning systems have grown significantly with the increasing reliance on sensitive user data for training large-scale models. This paper introduces a novel framework combining Probably Approximately Correct (PAC) Privacy with zero-knowledge proofs (ZKPs) to provide verifiable privacy guarantees in trustless computing environments. Our approach addresses the limitations of traditional privacy-preserving techniques by enabling users to verify both the correctness of computations and the proper application of privacy-preserving noise, particularly in cloud-based systems. We leverage non-interactive ZKP schemes to generate proofs that attest to the correct implementation of PAC privacy mechanisms while maintaining the confidentiality of proprietary systems. Our results demonstrate the feasibility of achieving verifiable PAC privacy in outsourced computation, offering a practical solution for maintaining trust in privacy-preserving machine learning and database systems while ensuring computational integrity.
This paper introduces DMind-3, a sovereign Edge-Local-Cloud intelligence stack designed to secure irreversible financial execution in Web3 environments against adversarial risks and strict latency constraints. While existing cloud-centric assistants compromise privacy and fail under network congestion, and purely local solutions lack global ecosystem context, DMind-3 resolves these tensions by decomposing capability into three cooperating layers: a deterministic signing-time intent firewall at the edge, a private high-fidelity reasoning engine on user hardware, and a policy-governed global context synthesizer in the cloud. We propose policy-driven selective offloading to route computation based on privacy sensitivity and uncertainty, supported by two novel training objectives: Hierarchical Predictive Synthesis (HPS) for fusing time-varying macro signals, and Contrastive Chain-of-Correction Supervised Fine-Tuning (C$^3$-SFT) to enhance local verification reliability. Extensive evaluations demonstrate that DMind-3 achieves a 93.7% multi-turn success rate in protocol-constrained tasks and superior domain reasoning compared to general-purpose baselines, providing a scalable framework where safety is bound to the edge execution primitive while maintaining sovereignty over sensitive user intent.
Abstract: The research presents a Privacy-Preserving Data Exchange (PPDE) framework for electronic health records (EHRs) that integrates elliptic-curve cryptography (ECC), zero-knowledge proofs (ZKPs), and capability tokens on a permissioned blockchain to create a cohesive, policy-compliant data-sharing workflow. In this system, IoT gateways establish ECC-based session keys to encrypt measurements at the edge, while only cryptographic hashes and pointers to the encrypted data are stored on a consortium blockchain, ensuring data confidentiality with tamper-evident integrity and auditable provenance. Healthcare providers issue Access Request Transactions that include ECC signatures and ZKPs to prove policy compliance (such as patient consent and role-based access) without revealing sensitive details. Off-chain ZKPs validate authorization decisions, with on-chain records providing verifiable evidence of conformance and access history, and a capability token is granted to authorize future data access within defined scopes and time windows. The framework emphasizes end-to-end confidentiality, privacy-preserving authorization, and tamper resistance through the blockchain. Our evaluation analyzes network throughput, end-to-end delay, packet delivery ratio, scalability, and energy efficiency, with particular attention to the overhead from blockchain operations, ECC, and ZKP verification. Results show improved privacy and security for EHR data, with only nominal overhead relative to the privacy and integrity gains, and favorable scalability and energy performance in realistic deployments.
This article explores the role of zero-knowledge cryptographic proofs as a basic trust mechanism for financial and government digital services. The theoretical section explains how such proofs shift compliance verification from a "reveal data and verify" mode to a "prove property and admit access to service" mode, thereby reducing transaction costs, mitigating information asymmetries, and limiting agency costs. Drawing on insights from new institutional economics and mechanism theory, it demonstrates how formalized verifiability improves rule robustness, makes truthful reporting individually rational, and reduces the negative externalities of leaks. The analytical section systematizes classes of constructions, highlighting tradeoffs between proof size, latency, the need for trusted configuration, and operational risks. The practical section describes applications in payment infrastructure, lending, insurance, cross-border settlements, digital identity, and ledger management: range constraint verification, threshold and attribute verification, verifiable computation, and selective disclosure. It is demonstrated that with proper design, it is possible to combine data minimization with targeted transparency and effective enforcement, including in projects involving central bank digital money and pan-European identity wallets. Implementation metrics are discussed: marginal cost of proof and verification, average latency, fault tolerance, and the proportion of cases where primary documents are replaced with proof of property.
Abstract Electronic health records (EHRs) capture the entire patient data history that enables early diagnosis, predictive analytics,improved co-ordination between health care providers,etc. However, centralized storage of EHR exposes the sensitive patient data to breaches while regulations such as GDPR Article 17 “right to be forgotten” and HIPAA 6-year retention limits sharing of data across different institutions. This systematic review consolidates 81 peer- reviewed studies (2015–2024) across different domains namely zero-knowledge proofs (ZKPs), blockchain consensus, trusted cloud execution, and regulatory compliance to propose a three-tier integrated framework that helps in regulatory compliant health care data sharing, yet preserving the privacy.The first tier is to generate ZKPs on the client side and redact personal information with chameleon hashes. The second tier anchors metadata hashes on PBFT blockchain with $f=\lfloor(n-1)/3\rfloor$ fault tolerance. The third tier stores data with an attribute-based encryption (ABE) off-chain on the cloud, integrated with FHIR/HL7 standards. It allows selective sharing, balances blockchain immutability with deletion via ZKP invalidation. The proposed architecture maps tools like zk-SNARKs/Circom for proofs, Hyperledger Fabric for blockchain, AWS KMS for keys. Challenges include lack of real-world testing, achieving proof generation latency (2-15 seconds), and scaling needs via Layer-2 hybrid consensus prototypes. \textbf{Keywords:} Zero-knowledge proofs, blockchain PBFT consensus, GDPR-HIPAA compliance, FHIR interoperability, attribute-based encryption.
Unlike Ethereum, which was conceived as a general-purpose smart-contract platform, Bitcoin was designed primarily as a transaction ledger for its native currency, which limits programmability for conditional applications. This constraint is particularly evident when considering oracles, mechanisms that enable Bitcoin contracts to depend on exogenous events. This paper investigates whether new oracle designs have emerged for Bitcoin Layer 1 since the 2015 transition to the Ethereum smart contracts era and whether subsequent Bitcoin improvement proposals have expanded oracles' implementability. Using Scopus and Web of Science searches, complemented by Google Scholar to capture protocol proposals, we observe that the indexed academic coverage remains limited, and many contributions circulate outside journal venues. Within the retrieved corpus, the main post-2015 shift is from multisig-style, which envisioned oracles as co-signers, toward attestation-based designs, mainly represented by Discreet Log Contracts (DLCs), which show stronger Bitcoin community compliance, tool support, and evidence of practical implementations in real-world scenarios such as betting and prediction-market mechanisms.