Tuxedo: Maximizing Smart Contract Computation in PoW Blockchains

2021 ◽  
Vol 5 (3) ◽  
pp. 1-30
Author(s):  
Sourav Das ◽  
Nitin Awathare ◽  
Ling Ren ◽  
Vinay J. Ribeiro ◽  
Umesh Bellur
Keyword(s):  
System Parameter ◽  
Security Analysis ◽  
Scaling Up ◽  
Interarrival Time ◽  
End To End Delay ◽  
Smart Contract ◽  
Key Innovation ◽  
Synchronous Network ◽  
And Performance ◽  
Harmful Effects

Proof-of-Work (PoW) based blockchains typically allocate only a tiny fraction (e.g., less than 1% for Ethereum) of the average interarrival time (I) between blocks for validating smart contracts present in transactions. In such systems, block validation and PoW mining are typically performed sequentially, the former by CPUs and the latter by ASICs. A trivial increase in validation time (τ) introduces the popularly known Verifier's Dilemma, and as we demonstrate, causes more forking and hurts fairness. Large τ also reduces the tolerance for safety against a Byzantine adversary. Solutions that offload validation to a set of non-chain nodes (a.k.a. off-chain approaches) suffer from trust and performance issues that are non-trivial to resolve. In this paper, we present Tuxedo, the first on-chain protocol to theoretically scale τ/I ≈1 in PoW blockchains. The key innovation in Tuxedo is to perform CPU-based block processing in parallel to ASIC mining. We achieve this by allowing miners to delay validation of transactions in a block by up to ζ blocks, where ζ is a system parameter. We perform security analysis of Tuxedo considering all possible adversarial strategies in a synchronous network with maximum end-to-end delay Δ and demonstrate that Tuxedo achieves security equivalent to known results for longest chain PoW Nakamoto consensus. Our prototype implementation of Tuxedo atop Ethereum demonstrates that it can scale τ without suffering the harmful effects of naive scaling up of τ/I in existing blockchains

scholarly journals Adjacency-Hash-Table Based Public Auditing for Data Integrity in Mobile Cloud Computing

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Wenqi Chen ◽  
Hui Tian ◽  
Chin-Chen Chang ◽  
Fulin Nan ◽  
Jing Lu
Keyword(s):  
Cloud Computing ◽  
High Speed ◽  
Security Analysis ◽  
Hash Table ◽  
The State ◽  
Public Auditing ◽  
The Arts ◽  
High Speed Data ◽  
And Performance ◽  
Data Updating

Cloud storage, one of the core services of cloud computing, provides an effective way to solve the problems of storage and management caused by high-speed data growth. Thus, a growing number of organizations and individuals tend to store their data in the cloud. However, due to the separation of data ownership and management, it is difficult for users to check the integrity of data in the traditional way. Therefore, many researchers focus on developing several protocols, which can remotely check the integrity of data in the cloud. In this paper, we propose a novel public auditing protocol based on the adjacency-hash table, where dynamic auditing and data updating are more efficient than those of the state of the arts. Moreover, with such an authentication structure, computation and communication costs can be reduced effectively. The security analysis and performance evaluation based on comprehensive experiments demonstrate that our protocol can achieve all the desired properties and outperform the state-of-the-art ones in computing overheads for updating and verification.

Secretly Pruned Convolutional Codes: Security Analysis and Performance Results

2016 ◽  
Vol 11 (7) ◽  
pp. 1500-1514 ◽  
Author(s):  
Nicholas Kolokotronis ◽  
Alexandros Katsiotis ◽  
Nicholas Kalouptsidis
Keyword(s):  
Security Analysis ◽  
Convolutional Codes ◽  
And Performance ◽  
Performance Results

scholarly journals Remote Data Possession Checking Scheme with Supporting Efficient Group User Authority Management for Shared Cloud Data

2021 ◽  
Author(s):  
Yilin Yuan ◽  
Jianbiao Zhang ◽  
Wanshan Xu ◽  
Xiao Wang ◽  
Yanhui Liu
Keyword(s):  
Security Analysis ◽  
Public Auditing ◽  
Cloud Data ◽  
The Public ◽  
Shared Data ◽  
Identity Based ◽  
And Performance ◽  
Data Auditing ◽  
Data Checking ◽  
Remote Data

Abstract Under the shared big data environment, most of the existing data auditing schemes rarely consider the authorization management of group users. Meanwhile, how to deal with the shared data integrity is a problem that needs to be pondered. Thus, in this paper, we propose a novel remote data checking possession scheme which achieves group authority management while completing the public auditing. To perform authority management work, we introduce a trusted entity – group manager. We formalize a new algebraic structure operator named authorization invisible authenticator (AIA). Meanwhile, we provide two versions of AIA scheme: basic AIA scheme and standard AIA scheme. The standard AIA scheme is constructed based on the basic AIA scheme and user information table (UIT), with advanced security and wider applicable scenarios. By virtue of standard AIA scheme, the group manager can perfectly and easily carry out authority management, including enrolling, revoking, updating. On the basis of the above, we further design a public auditing scheme for non-revoked users’ shared data. The scheme is based on identity-based encryption (IBE), which greatly reduce the necessary certificate management cost. Furthermore, the detailed security analysis and performance evaluation demonstrate that the scheme is safe and feasible.

scholarly journals ECLB: Edge-Computing-Based Lightweight Blockchain Framework for Mobile Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qingqing Xie ◽  
Fan Dong ◽  
Xia Feng
Keyword(s):  
Mobile Devices ◽  
Security Analysis ◽  
Edge Computing ◽  
Mobile Systems ◽  
Superior Performance ◽  
Consensus Protocol ◽  
Open Problems ◽  
Blockchain Technology ◽  
Natural Solution ◽  
And Performance

The blockchain technology achieves security by sacrificing prohibitive storage and computation resources. However, in mobile systems, the mobile devices usually offer weak computation and storage resources. It prohibits the wide application of the blockchain technology. Edge computing appears with strong resources and inherent decentralization, which can provide a natural solution to overcoming the resource-insufficiency problem. However, applying edge computing directly can only relieve some storage and computation pressure. There are some other open problems, such as improving confirmation latency, throughput, and regulation. To this end, we propose an edge-computing-based lightweight blockchain framework (ECLB) for mobile systems. This paper introduces a novel set of ledger structures and designs a transaction consensus protocol to achieve superior performance. Moreover, considering the permissioned blockchain setting, we specifically utilize some cryptographic methods to design a pluggable transaction regulation module. Finally, our security analysis and performance evaluation show that ECLB can retain the security of Bitcoin-like blockchain and better performance of ledger storage cost in mobile devices, block mining computation cost, throughput, transaction confirmation latency, and transaction regulation cost.

scholarly journals Watching television in a home environment: effect on children’s attention, comprehension and behavior

2019 ◽  
Author(s):  
Sarah E Rose ◽  
Alexandra Lamont ◽  
Nicholas Reyland
Keyword(s):  
Problem Solving ◽  
Ecological Validity ◽  
Experimental Studies ◽  
Tv Viewing ◽  
Facilitation Effect ◽  
Environment Effect ◽  
And Performance ◽  
And Behavior ◽  
Harmful Effects ◽  
Problem Solving Task

Correlational studies have suggested some harmful effects of television (TV) viewing in early childhood, especially for the viewing of fast-paced entertainment programs. However, this has not been consistently supported by experimental studies, many of which have lacked ecological validity. The current study explores the effects of pace of program on the attention, problem solving and comprehension of 41 3- and 4-year-olds using an ecologically valid experimental design. Children were visited twice at home; on each visit they were shown an episode of a popular animated entertainment program which differed in pace: one faster paced, one slower paced. Children’s behavior was coded for attention and arousal during viewing, attention, effort and performance after viewing during a problem-solving task, and comprehension of the program. The faster paced program was attended to more, but this had no impact on comprehension. Although 3-year-olds showed more attention and effort on the problem-solving task after watching the slower program, both 3- and 4-year-olds completed more problems successfully after watching the faster program. The results provide evidence to counter the ‘harm’ perceived in young children watching fast-paced entertainment programs as where differences were found it was the fast-paced program which appeared to have a cognitive facilitation effect.

scholarly journals A secure dynamic adaptive routing technique using game theory in wireless sensor network

2018 ◽  
Vol 7 (2) ◽  
pp. 768
Author(s):  
Muruganandam. A ◽  
Anitha. R
Keyword(s):  
Game Theory ◽  
Wireless Sensor Network ◽  
Sensor Network ◽  
Data Security ◽  
Wireless Sensor ◽  
Wireless Data ◽  
End To End Delay ◽  
And Performance ◽  
Secured Communication ◽  
Significant Concentration

A Wireless Sensor Network (WSNs) is popular developing the field in industrial and other major markets. Wireless data security is the central theme in the WSNs application where security of transmitted data is more concerned. Due to the significant concentration of energy efficiency and performance analysis in WSN, providing secured communication is a challenging issue. To overcome this interdependent problem Game theory can be used. Game theory is applied here to select different routes to transfer the data from source to destination. The performance of the WSNs can be increased by providing security for transmitted data. The graph for throughput, end to end delay, delivery, and packet loss ratio are generated using NS2 simulation tool.

scholarly journals Suggested Integral Analysis for Chaos-Based Image Cryptosystems

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 815 ◽  
Author(s):  
Miguel Angel Murillo-Escobar ◽  
Manuel Omar Meranza-Castillón ◽  
Rosa Martha López-Gutiérrez ◽  
César Cruz-Hernández
Keyword(s):  
Security Analysis ◽  
Analysis Framework ◽  
Integral Analysis ◽  
Aes Algorithm ◽  
Digital Chaos ◽  
Important Challenge ◽  
Encryption Algorithms ◽  
And Performance ◽  
First Time ◽  
New Algorithms

Currently, chaos-based cryptosystems are being proposed in the literature to provide confidentiality for digital images, since the diffusion effect in the Advance Encryption Standard (AES) algorithm is weak. Security is the most important challenge to assess in cryptosystems according to the National Institute of Standard and Technology (NIST), then cost and performance, and finally algorithm and implementation. Recent chaos-based image encryption algorithms present basic security analysis, which could make them insecure for some applications. In this paper, we suggest an integral analysis framework related to comprehensive security analysis, cost and performance, and the algorithm and implementation for chaos-based image cryptosystems. The proposed guideline based on 20 analysis points can assist new cryptographic designers to present an integral analysis of new algorithms. Future comparisons of new schemes can be more consistent in terms of security and efficiency. In addition, we present aspects regarding digital chaos implementation, chaos validation, and key definition to improve the security of the overall cryptosystem. The suggested guideline does not guarantee security, and it does not intend to limit the liberty to implement new analysis. However, it provides for the first time in the literature a solid basis about integral analysis for chaos-based image cryptosystems as an effective approach to improve security.

scholarly journals Fine-Grained Control-Flow Integrity Based on Points-to Analysis for CPS

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Weizhong Qiang ◽  
Shizhen Wang ◽  
Hai Jin ◽  
Jiangying Zhong
Keyword(s):  
Security Analysis ◽  
Control Flow ◽  
Security And Privacy ◽  
Code Reuse ◽  
Fine Grained ◽  
Function Calls ◽  
Legitimate Target ◽  
Control Flow Integrity ◽  
Target Set ◽  
And Performance

A cyber-physical system (CPS) is known as a mix system composed of computational and physical capabilities. The fast development of CPS brings new security and privacy requirements. Code reuse attacks that affect the correct behavior of software by exploiting memory corruption vulnerabilities and reusing existing code may also be threats to CPS. Various defense techniques are proposed in recent years as countermeasures to emerging code reuse attacks. However, they may fail to fulfill the security requirement well because they cannot protect the indirect function calls properly when it comes to dynamic code reuse attacks aiming at forward edges of control-flow graph (CFG). In this paper, we propose P-CFI, a fine-grained control-flow integrity (CFI) method, to protect CPS against memory-related attacks. We use points-to analysis to construct the legitimate target set for every indirect call cite and check whether the target of the indirect call cite is in the legitimate target set at runtime. We implement a prototype of P-CFI on LLVM and evaluate both its functionality and performance. Security analysis proves that P-CFI can mitigate the dynamic code reuse attack based on forward edges of CFG. Performance evaluation shows that P-CFI can protect CPS from dynamic code reuse attacks with trivial time overhead between 0.1% and 3.5% (Copyright © 2018 John Wiley & Sons, Ltd.).

scholarly journals Achieving Incentive, Security, and Scalable Privacy Protection in Mobile Crowdsensing Services

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jinbo Xiong ◽  
Rong Ma ◽  
Lei Chen ◽  
Youliang Tian ◽  
Li Lin ◽  
...  
Keyword(s):  
Data Privacy ◽  
Differential Privacy ◽  
Homomorphic Encryption ◽  
Security Analysis ◽  
Mobile Crowdsensing ◽  
Sensing Data ◽  
Noise Data ◽  
And Performance ◽  
Further Development ◽  
The Internet Of Things

Mobile crowdsensing as a novel service schema of the Internet of Things (IoT) provides an innovative way to implement ubiquitous social sensing. How to establish an effective mechanism to improve the participation of sensing users and the authenticity of sensing data, protect the users’ data privacy, and prevent malicious users from providing false data are among the urgent problems in mobile crowdsensing services in IoT. These issues raise a gargantuan challenge hindering the further development of mobile crowdsensing. In order to tackle the above issues, in this paper, we propose a reliable hybrid incentive mechanism for enhancing crowdsensing participations by encouraging and stimulating sensing users with both reputation and service returns in mobile crowdsensing tasks. Moreover, we propose a privacy preserving data aggregation scheme, where the mediator and/or sensing users may not be fully trusted. In this scheme, differential privacy mechanism is utilized through allowing different sensing users to add noise data, then employing homomorphic encryption for protecting the sensing data, and finally uploading ciphertext to the mediator, who is able to obtain the collection of ciphertext of the sensing data without actual decryption. Even in the case of partial sensing data leakage, differential privacy mechanism can still ensure the security of the sensing user’s privacy. Finally, we introduce a novel secure multiparty auction mechanism based on the auction game theory and secure multiparty computation, which effectively solves the problem of prisoners’ dilemma incurred in the sensing data transaction between the service provider and mediator. Security analysis and performance evaluation demonstrate that the proposed scheme is secure and efficient.

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