Current mobile System-on-Chip (SoC) architectures suffer from a fundamental âReactive Polling Tax,â where high-level software must frequently interrupt low-power hardware states to query rawsensor telemetry. This paper introduces the Contextual Neural Bus (CNB), a dedicated, asynchronous hardware-level interconnect designed to shift context awareness from volatile software cycles to deterministic silicon logic. By utilizing a decentralized multi-modal fusion layer, the CNB generates Universal Intent Tokens (UITs)â64-bit cryptographic primitives that represent verified user states at the physical layer. Unlike legacy co-processors that merely buffer data, the CNB integrates a Hardware-Resident Zero-Knowledge Proof (ZKP) Generator to provide mathematical certainty of user intentwhile physically isolating raw biometric and environmental telemetry within a secure silicon enclave. Preliminary simulations using a digital-twin SoC model indicate a 90.8% reduction in interrupt driven power consumption, effectively achieving âEnergy-Neutral Privacyâ by utilizing the resulting power surplus to offset cryptographic overhead. Furthermore, the architecture introduces Predictive L3 Cache Pre-warming, which anticipates user interactions to virtually eliminate âcold-startâ application latencies. By anchoring proactive computing in the deterministic reliability of silicon, this work establishes a scalable, privacy-first path toward zero-latency, energy-autonomous mobile ecosystems.
ABSTRACT The emergence of wireless technology brought about enhanced communication across various devices, resulting in the demand for efficient and reliable wireless networks, like wireless mesh networks (WMNs) and mobile Adâhoc Networks (MANETs). MANETs are known for their decentralized nature, rapid deployment, infrastructureâless operation, adaptability, and ease of use in several applications and outdoor events. Despite their flexibility, they often face challenges relating to security vulnerabilities, together with blackhole and grayhole attacks, and tradeâoffs in terms of performance relating to reliability and integrity. This paper proposes an improved, innovative routing protocol for Adâhoc OnâDemand Distance Vector (AODV) by infusion of blockchain's proof of stake (PoS) consensus mechanism named PoSAODV, whose objective is to enhance security, energyâefficiency, and adaptability while reducing packet loss rate, routing overheads, and increasing throughput. Smart contractâbased validator selection was utilized to ensure fairness and reduce blackhole and grayhole attacks. The result obtained through simulation demonstrates that PoSAODV outperforms the original AODV by reduced latency of 0.79 ms , average throughput of 45 Mbps , and packet delivery ratio of 80%â100% in both unsafe and safe environments. This makes PoSAODV suitable for resourceâconstrained adâhoc networks with dynamic topologies.
Popular technologies such as blockchain and zero-knowledge proof, which have already entered the enterprise space, heavily use cryptography as the core of their protocol stack. One of the most used systems in this regard is Elliptic Curve Cryptography, precisely the point multiplication operation, which provides the security assumption for all applications that use this system. As this operation is computationally intensive, one solution is to offload it to specialized accelerators to provide better throughput and increased efficiency. In this paper, we explore the use of Field Programmable Gate Arrays (FPGAs) and the High-Level Synthesis framework of AMD Vitis in designing an elliptic curve point arithmetic unit (point adder) for the secp256k1 curve. We show how task-level parallel programming and data streaming are used in designing a RISC processor-like architecture to provide pipeline parallelism and increase the throughput of the point adder unit. We also show how to efficiently use the proposed processor architecture by designing a point multiplication scheduler capable of scheduling multiple batches of elliptic curve points to utilize the point adder unit efficiently. Finally, we evaluate our design on an AMD-Xilinx Alveo-family FPGA and show that our point arithmetic processor has better throughput and frequency than related work.
Ethereum is currently the second largest blockchain by market capitalization and a popular platform for cryptocurrencies. As it has grown, the high value present and the anonymity afforded by the technology have led Ethereum to become a hotbed for various cybercrimes. This paper seeks to understand how these fraudulent schemes may be characterized and develop methods for detecting them. One key feature introduced by Ethereum is the ability to use programmable smart contracts to execute code on the blockchain. A common use of smart contracts is implementing fungible tokens with the ERC-20 interface. Such tokens can be used to impersonate legitimate tokens and defraud users. By parsing the event logs emitted by these ERC-20 contracts over 20 different periods of 100K blocks, we construct token transfer graphs for each of the available ERC-20 tokens on the blockchain. By analyzing these graphs, we find a set of characteristics by which suspicious contracts are distinguished from legitimate ones. These observations result in a simple model that can identify scam contracts with an average of 88.7% accuracy. This suggests that the mechanism by which fraudulent schemes function strongly correlates with their transfer graphs and that these graphs may be used to improve scam-detection mechanisms, contributing to making Ethereum safer.
A connected loopless graph is 2-edge-connected if it remains connected after the removal of at most one of its edges. Many combinatorial optimization problems seek, for a given graph with costs on its edges, a spanning subgraph satisfying certain connectivity constraints. The minimum 2-edge-connected spanning subgraph problem (2-ECSSP) is a problem of this type. It can be formulated as an integer linear program that selects edges of minimum total cost satisfying the restriction that every cut of the given graph is covered by at least two of the selected edges. This problem is known to be NP-hard. This thesis develops rounding algorithms for three variants of 2-ECSSP, focusing on rounding half-integral solutions of the corresponding linear relaxation. This family of solutions often yields the largest known integrality ratio for various subproblems of 2-ECSSP. The first problem we investigate is the half-integral 2-ECSSP with unrestricted costs. We develop a novel 5/3-rounding that, to the best of our knowledge, is the first one with a factor better than 2. Moreover, we design a reduction scheme, restricting the problem to 4-edge-connected graphs with maximum degree at most five. Then, we study the matching augmentation problem (MAP), a subproblem of 2-ECSSP in which the edge costs are either 0 or 1 and the zero cost edges define a matching. We survey a better-than-2-approximation, obtained in 2022 by Bamas, Drygala, and Svensson, presenting a comprehensive proof of their result and determining an improved factor. Additionally, we address conjectures posed in their work and present computational experiments to support our findings. Finally, we discuss the 2-edge-connected spanning multisubgraph problem (2-ECSMP), a variation of 2-ECSSP in which multiple copies of the same edge can be selected. We survey a recent work by Boyd et al. on a 4/3-rounding for the half-integral 2-ECSMP and leverage their techniques to prove novel decomposition theorems for 4-regular 4-edge-connected graphs. Finally, we pose two conjectures concerning extensions of the decomposition results, suggesting new research directions.
Yutian Chen, Cong Peng, Yu Dai, Min Luo · 5 authors
Multi-scalar multiplication (MSM) is an important building block in most of elliptic-curve-based zero-knowledge proof systems, such as Groth16 and PLONK. Recently, Lu et al. proposed cuZK, a new parallel MSM algorithm on GPUs. In this paper, we revisit this scheme and present a new GPU-based implementation to further improve the performance of MSM algorithm. First, we propose a novel method for mapping scalars into Pippengerâs bucket indices, largely reducing the number of buckets compared to the original Pippenger algorithm. Second, in the case that memory is sufficient, we develop a new efficient algorithm based on homogeneous coordinates in the bucket accumulation phase. Moreover, our accumulation phase is load-balanced, which means the parallel speedup ratio is almost linear growth as the number of device threads increases. Finally, we also propose a parallel layered reduction algorithm for the bucket aggregation phase, whose time complexity remains at the logarithmic level of the number of buckets. The implementation results over the BLS12-381 curve on the V100 graphics card show that our proposed algorithm achieves up to 1.998x, 1.821x and 1.818x speedup compared to cuZK at scales of 221, 222, and 223, respectively.
The primary trend in the development of modern information technologies is the migration of computations to the cloud, making distributed computing the dominant strategy for information processing. In particular, this poses the challenge of reliable distributed data storage. A well-known approach to solving the problem of distributed data storage is blockchain or, more generally, distributed ledger technology. A key challenge of this technology is creating an effective mechanism for the global numbering of registry records. The complexity of solving this problem results from the fundamental limitations of distributed computing â the inability to accurately synchronize distributed computing processes and the limitations resulting from the CAP theorem for distributed data stores. The authors attempt to circumvent the mentioned limitations based on the hypothesis that such limitations can be overcome by considering both the network topology and narrowing the class of distributed systems to distributed registers. The work is based on methods of modeling distributed computing, particularly the model of space-time diagrams proposed by L. Lamport. This model allows us to introduce such a tool as logical clocks, including Lamport's logical clock algorithm. Unfortunately, Lamport's logical clock algorithm allows assigning a common timestamp to different events if they are concurrent. The paper proposes an algorithm that is a composition of Lamport's clock algorithm and the wave algorithm, which is not only a logical clock but also assigns different timestamps to different events. Thus, this algorithm provides a mechanism for the global numbering of entries of distributed ledger replicas. A problematic issue remains gaps in the series of ledger entry numbers. Thus, the paper proposes an effective mechanism for the global numbering of records of a distributed register and identifies a shortcoming of this mechanism. Further study is to identify specific conditions in terms of network topology that would ensure the absence of the mentioned shortcoming.
Protecting the privacy of blockchain transactions is extremely important for users. Stealth address protocols (SAP) allow users to receive assets via stealth addresses that they do not associate with their stealth meta-addresses. SAP can be generated using different cryptographic approaches. DKSAP uses an elliptic curve multiplication and hashing of the resulting shared secret. Another approach is to use a elliptic curve pairing. This paper presents four SA protocols that use elliptic curve pairing as a cryptographic solution. ECPDKSAPs are pairing-based protocols that include viewing key and spending key, while ECPSKSAP is a pairing-based protocol that uses a single key with which spending and the viewing key are derived. We find that ECPDKSAPs give significantly better results than DKSAP with the view tag. The best results are achieved with Protocol 3 (Elliptic Curve Pairing Dual Key Stealth Address Protocol), which is Ethereum-friendly. ECPSKSAP is significantly slower, but it provides an interesting theoretical result as it uses only one private key.
Amal Abdulbaqi Maryoosh, Ahmed Abd Ali Abdulkadhim, Muntaha AbdulzahraHatem
Block chain is a technology for securely storing data in a manner that makes system changes or hacks impossible or difficult. Numerous organizations have adopted this technology, which utilizes a peer-to-peer distributed network. Using a decentralized peer-to-peer network to operate. A block chain is a collection of linked computer systems that operate as a distributed ledger of transactions. Every new transaction that happens on the block chain is copied to each participant's ledger, and each block on the chain is made up of numerous transactions. This paper aims to explain block chain technology, including its uses and difficulties.
Orestis Alpos, Christian Cachin, Simon Holmgaard Kamp, Jesper Buus Nielsen
We present simple and practical protocols for generating randomness as used by asynchronous total-order broadcast. The protocols are secure in a proof-of-stake setting with dynamically changing stake. They can be plugged into existing protocols for asynchronous total-order broadcast and will turn these into asynchronous total-order broadcast with dynamic stake. Our contribution relies on two important techniques. The paper "Random Oracles in Constantinople: Practical Asynchronous Byzantine Agreement using Cryptography" [Cachin, Kursawe, and Shoup, PODC 2000] has influenced the design of practical total-order broadcast through its use of threshold cryptography. However, it needs a setup protocol to be efficient. In a proof-of-stake setting with dynamic stake this setup would have to be continually recomputed, making the protocol impractical. The work "Asynchronous Byzantine Agreement with Subquadratic Communication" [Blum, Katz, Liu-Zhang, and Loss, TCC 2020] showed how to use an initial setup for broadcast to asymptotically efficiently generate sub-sequent setups. The protocol, however, resorted to fully homomorphic encryption and was therefore not practically efficient. We adopt their approach to the proof-of-stake setting with dynamic stake, apply it to the Constantinople paper, and remove the need for fully homomorphic encryption. This results in simple and practical proof-of-stake protocols.
Abstract During the last years, several card-based Zero-Knowledge Proof (ZKP) protocols for Nikoliâs puzzles have been designed. Although there are relatively simple card-based ZKP protocols for a number of puzzles, such as Sudoku and Kakuro, some puzzles face difficulties in designing simple protocols. For example, Slitherlink requires novel and elaborate techniques to construct a protocol. In this study, we focus on three Nikoli puzzles: Nurikabe, Hitori, and Heyawake. To date, no card-based ZKP protocol for these puzzles has been developed, partially because they have a relatively tricky rule that colored cells should form a connected area (namely a polyomino); this rule, sometimes referred to as âBundan-kinâ (in Japanese), complicates the puzzles, as well as facilitating difficulties in designing card-based ZKP protocols. We address this challenging task and propose a method for verifying the connectivity of hidden colored cells in a ZKP manner, such that we construct card-based ZKP protocols for the three puzzles.
Shikaku is a pencil puzzle consisting of a rectangular grid, with some cells containing a number. The player has to partition the grid into rectangles such that each rectangle contains exactly one number equal to the area of that rectangle. In this paper, we propose two physical zero-knowledge proof protocols for Shikaku using a deck of playing cards, which allow a prover to physically show that he/she knows a solution of the puzzle without revealing it. Most importantly, in our second protocol we develop a general technique to physically verify a rectangle-shaped area with a certain size in a rectangular grid, which can be used to verify other problems with similar constraints.
Chrysoula Stathakopoulou, Tudor David, Matej PavloviÄ, Marko VukoliÄ
This paper presents Mir-BFT, a robust Byzantine fault-tolerant (BFT) total order broadcast protocol aimed at maxi-mizing throughput on wide-area networks (WANs), targetingdeployments in decentralized networks, such as permissionedand Proof-of-Stake permissionless blockchain systems. Mir-BFT is the first BFT protocol that allows multiple lead-ers to propose request batches independently (i.e., parallelleaders), while effectively precluding performance degrada-tion due to request duplication by rotating the assignmentof a partitioned request hash space to leaders. As this mech-anism removes the single-leader bandwidth bottleneck andexposes a computation bottleneck related to authenticatingclients even on a WAN, our protocol further boosts through-put using a client signature verification sharding optimization.Our evaluation shows that Mir-BFT outperforms state-of-the-art single-leader protocols and orders more than 60000 signedBitcoin-sized (500-byte) transactions per second on a widelydistributed setup (100 nodes, 1 Gbps WAN) with typical la-tencies of few seconds. Moreover, our evaluation exposesthe impact of duplicate requests on parallel leader protocolswhich Mir-BFT eliminates. We also evaluate Mir-BFT un-der different crash and Byzantine faults, demonstrating itsperformance robustness. Mir-BFT relies on classical BFT protocol constructs, whichsimplifies reasoning about its correctness. Specifically, Mir-BFT is a generalization of the celebrated and scrutinizedPBFT protocol. In a nutshell, Mir-BFT follows PBFT âsafety-wiseâ, with changes needed to accommodate novel featuresrestricted to PBFT liveness.
Daniel M. Kane, Andreas Fackler, Adam GÄ gol, Damian Straszak
There has been recently a lot of progress in designing efficient partially synchronous BFT consensus protocols that are meant to serve as core consensus engines for Proof of Stake blockchain systems. While the state-of-the-art solutions attain virtually optimal performance under this theoretical model, there is still room for improvement, as several practical aspects of such systems are not captured by this model. Most notably, during regular execution, due to financial incentives in such systems, one expects an overwhelming fraction of nodes to honestly follow the protocol rules and only few of them to be faulty, most likely due to temporary network issues. Intuitively, the fact that almost all nodes behave honestly should result in stronger confidence in blocks finalized in such periods, however it is not the case under the classical model, where finality is binary. We propose Highway, a new consensus protocol that is safe and live in the classical partially synchronous BFT model, while at the same time offering practical improvements over existing solutions. Specifically, block finality in Highway is not binary but is expressed by fraction of nodes that would need to break the protocol rules in order for a block to be reverted. During periods of honest participation finality of blocks might reach well beyond 1/3 (as what would be the maximum for classical protocols), up to even 1 (complete certainty). Having finality defined this way, Highway offers flexibility with respect to the configuration of security thresholds among nodes running the protocol, allowing nodes with lower thresholds to reach finality faster than the ones requiring higher levels of confidence.
Blockmania is a byzantine consensus protocol. Nodes emit blocks forming a directed acyclic graph (block DAG) that is subsequently interpreted by each node separately to ensure consensus with safety, liveness and finality. The resulting system has communication complexity $O(N^2)$ even in the worse case, and very low constant factors --- as compared to $O(N^4)$ for PBFT; it is leaderless; and network operations do not depend on the composition of the quorum or node stake. This makes Blockmania very efficient (leading to over 400K transactions per second on a wide area network), and ideal for dynamic membership and flexible and non-interrupted proof-of-stake protocols. A X-Blockmania variant, has $O(N)$ communication cost but also higher latency $O(\log N)$.
This paper proposes a novel adaptation of blockchain technology to information exchanges among vehicles traveling in a platoon. The aim is to protect platoon member privacy and security while providing a rapid sharing of telemetry data. We have identified key protocols for a distributed cryptographic authentication among vehicles in transit within a platoon. This work heralds consideration of cyber-attack types on platoons and our proposed remedies.
Hyperledger Fabric (HLF) is a flexible permissioned blockchain platform designed for business applications beyond the basic digital coin addressed by Bitcoin and other existing networks. A key property of HLF is its extensibility, and in particular the support for multiple ordering services for building the blockchain. Nonetheless, the version 1.0 was launched in early 2017 without an implementation of a Byzantine fault-tolerant (BFT) ordering service. To overcome this limitation, we designed, implemented, and evaluated a BFT ordering service for HLF on top of the BFT-SMaRt state machine replication/consensus library, implementing also optimizations for wide-area deployment. Our results show that HLF with our ordering service can achieve up to ten thousand transactions per second and write a transaction irrevocably in the blockchain in half a second, even with peers spread in different continents.
Ayush Dubey, Greg D. Hill, Robert Escriva, Emin GĂŒn Sirer
Graph databases have become an increasingly common infrastructure component. Yet existing systems either operate on offline snapshots, provide weak consistency guarantees, or use expensive concurrency control techniques that limit performance. In this paper, we introduce a new distributed graph database, called Weaver, which enables efficient, transactional graph analyses as well as strictly serializable ACID transactions on dynamic graphs. The key insight that allows Weaver to combine strict serializability with horizontal scalability and high performance is a novel request ordering mechanism called refinable timestamps. This technique couples coarse-grained vector timestamps with a fine-grained timeline oracle to pay the overhead of strong consistency only when needed. Experiments show that Weaver enables a Bitcoin blockchain explorer that is 8x faster than Blockchain.info, and achieves 12x higher throughput than the Titan graph database on social network workloads and 4x lower latency than GraphLab on offline graph traversal workloads.
We present a protocol for controlling a shared ATM multicast tree supporting many-to-many communication. The protocol supports one or several ATM virtual channel connections (VCCs) of the many-to-many type. The number of VCCs is independent of the number of endpoints. The protocol guarantees that there is no interleaving on any VCC of the tree. The protocol also guarantees that the traffic contract associated with the VCCs is respected, thus making it possible to use ordinary VCCs of the constant bit rate (CBR), variable bit rate (VBR), or unspecified bit rate (UBR) class. No resequencing server or cell buffering inside the network is required, and all cell forwarding is performed at the ATM layer. We describe the protocol both informally and formally.