• Title/Summary/Keyword: smart contract

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Smart Contract Code Rewritter for Improving Safety of Function Calls (함수 호출의 안전성 향상을 돕는 스마트 계약 코드 재작성기)

  • Lee, Sooyeon;Jung, Hyungkun;Cho, Eun-Sun
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.29 no.1
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    • pp.67-75
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    • 2019
  • When a Solidity smart contract has a problem in calling a function of another contract, the fallback function is supposed to be executed automatically. However, it may be are arbitrarily created, with their behaviors unknown to developers, and fallback function execution is vulnerable to exploits by attackers. in In this paper, we propose a preprocessing based method to reduce the risk with less overhead of developers'. Developers mark the intention using the newly defined keywords in this paper, and the preprocessor reduces the risk by preprocessing the conditional variables and conditional statements according to the keywords.

A Study on Court Auction System using Ethereum-based Ether (이더리움 기반의 이더를 사용한 법원 경매 시스템에 관한 연구)

  • Kim, Hyo-Jong;Han, Kun-Hee;Shin, Seung-Soo
    • Journal of Convergence for Information Technology
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    • v.11 no.2
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    • pp.31-40
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    • 2021
  • Blockchain technology is also actively studied in the real estate transaction field, and real estate transactions have various ways. In this paper, we propose a model that simplifies the authentication procedure of auction systems using Ethereum's Ether to solve the problem of offline court auctions. The proposed model is written in Ethereum's Solidity language, the court registers the sale date and the sale date with the DApp browser, and the bidder accesses the address of the individual's wallet created through Metamask's private key. The bidder then selects the desired sale and enters the bid price amount to participate in the auction. The bidder's record of the highest bid price for the sale he wants is written on the Ethereum test network as a smart contract. and creates a block. Finally, smart contracts written on the network are distributed by the court auction manager to all nodes in the blockchain network, and each node in the blockchain network can be viewed and contract verified. As a result of analyzing the smart contracts of the proposed model and the performance of the system, there are fees incurred due to the creation and use of Ether on platforms using Ethereum, and participation. Ether's changes in value affect the price of the sale, resulting in inconsistent fees in smart contracts each time. However, in future work, we issue our own tokens to solve the market volatility problem and commission problem with the value change of Ether, and refine complex court auction systems.

A Study on Privilege Elevation Attack Management for Smart Transaction Security on BlockChain Etherium Based System

  • Min, Youn-A
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.4
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    • pp.65-71
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    • 2019
  • IAs smart device penetration rate is more than 90%, mobile transaction ratio using smart device is increasing. Smart contracts are used in various areas of real life including smart trading. By applying smart contracts to the platform for smart transactions through block-chain technology, the threat of hacking or forgery can be reduced. However, various threats to devices in smart transactions can pose a threat to the use of block chain Etherium, an important element in privilege and personal information management. Smart contract used in block chain Ethereum includes important information or transaction details of users. Therefore, in case of an attack of privilege elevation, it is very likely to exploit transaction details or forge or tamper with personal information inquiry. In this paper, we propose a detection and countermeasure method for privilege escalation attack, which is especially important for block chain for secure smart transaction using block chain Ethereum. When comparing the results of this study with the results of similar applications and researches, we showed about 12~13% improvement in performance and suggested the future countermeasures through packet analysis.

Improved Ad Hoc On-demand Distance Vector Routing(AODV) Protocol Based on Blockchain Node Detection in Ad Hoc Networks

  • Yan, Shuailing;Chung, Yeongjee
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.46-55
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    • 2020
  • Ad Hoc network is a special wireless network, mainly because the nodes are no control center, the topology is flexible, and the networking could be established quickly, which results the transmission stability is lower than other types of networks. In order to guarantee the transmission of data packets in the network effectively, an improved Queue Ad Hoc On-demand Distance Vector Routing protocol (Q-AODV) for node detection by using blockchain technology is proposed. In the route search process. Firstly, according to the node's daily communication record the cluster is formed by the source node using the smart contract and gradually extends to the path detection. Then the best optional path nodes are chained in the form of Merkle tree. Finally, the best path is chosen on the blockchain. Simulation experiments show that the stability of Q-AODV protocol is higher than the AODV protocol or the Dynamic Source Routing (DSR) protocol.

A Survey of Cryptocurrencies based on Blockchain

  • Kim, Junsang
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.2
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    • pp.67-74
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    • 2019
  • Since the announcement of bitcoin, new cryptocurrencies have been launched steadily and blockchain technology is also evolving with cryptocurrcies. In particular, security-related technologies such as consensus algorithm and hash algorithm have been improved and transaction processing speed has also been drastically improved to a level that can replace a centralized system. In addition, the advent of smart contract technology and the DApp platform also provides a means for cryptocurrency to decentralize social services beyond just payment. In this paper, we first describe the technologies for implementing cryptocurrency. And the major cryptocurrencies are described with a focus on the technical characteristics. In addition, the development of cryptocurrency technology is expanding the scope of use, so we tried to introduce various cryptocurrencies.

Implementation of University Point Distributed System based on Public Blockchain (퍼블릭 블록체인기반 대학 포인트 분산 시스템 개발)

  • Jung, Se-Hoon;Kim, Jeong Hoon;Sim, Chun-Bo
    • Journal of Korea Multimedia Society
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    • v.24 no.2
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    • pp.255-266
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    • 2021
  • Most common web or application system architectures have central network. As a result, central network can be supervised and controlled in all situation. And It has the advantage of easy to manage and fast to work. However, central network have a disadvantage of weak to security and unclear. In particular, many institutions used by web system be has many problems by central network. In this paper, we proposed blokchain technology based on ethereum to resolve of problem and trading structure that arise in cental network. We propose a decentralized application based on points including cryptocurrency functions and smart contract to the advantages of blockchain with a decentralized structure. The results of the performance experiment are as follows; It has shown the advantages of reliable use and security in a variety of environments(Windows, Ubuntu, Mac).

A Data Provenance System for Myanmar Rice Cycle Based on Ethereum Blockchain

  • Latt, Cho Nwe Zin;Rahmadika, Sandi;Rhee, Kyung-Hyune
    • Journal of Multimedia Information System
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    • v.8 no.1
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    • pp.35-44
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    • 2021
  • The Myanmar rice cycle's existing system is still relying on a third party to manage every rice data information from several organizations. It is inconvenient to supervise simultaneously due to the unreliability of information provided by organizations. Thus, the rice cycle's original data is challenging to be utterly trusted since irresponsible parties can manipulate the current state of information. Moreover, the applied system does not preserve a proper incentive for the involved parties. In this paper, we leverage the Ethereum blockchain to be adopted to tackle the aforementioned issues. The main objective is to build trust between parties in the Myanmar rice cycle system. Our proposed scheme allows customers to check and trace information about the rice cycle information without worrying about the integrity of the data. Furthermore, the authorized parties are also rewarded by the government through Ethereum smart contract features. Eventually, our scheme achieves traceability in the rice chain system and leads to the complete digitization and automation of the rice cycle information.

Implementation of Quality Management System for Wild-Simulated Ginseng Using Blockchain

  • Sung, Youngjun;Won, Yoojae
    • Journal of Information Processing Systems
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    • v.18 no.2
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    • pp.173-187
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    • 2022
  • A special government agency has been charged with implementing quality management to guarantee the quality of wild-simulated ginseng. However, these processes are carried out by use of documents, and this has resulted in information omission and high document management costs. To solve this problem, this study analyzed the existing quality management process by using a smart contract for the existing offline form and proposed a new quality management system for storing and managing all log data in the blockchain. This system reduced documentation management costs about quality management and recorded information in the previous step through the quality management steps, thus forming a step-by-step record chain. Experiments were conducted by implementing this system, which improved data integrity and reliability. Additionally, sensitive information, such as personal information, was included in the system by use of the off-chain technology.

A Design of IoT Service Access Control using the Smart Contract (스마트 컨트렉트를 사용한 IoT 서비스 접근제어 설계)

  • Kim, Mi-Sun;Seo, Jae-Hyun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.05a
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    • pp.279-282
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    • 2020
  • IoT 서비스는 이기종의 다양한 IoT 장치들로부터 수집된 데이터를 목적에 맞게 가공, 저장, 처리하여 사용자에게 서비스를 제공한다. 본 연구에서는 이기종의 IoT 서비스에서 공유 가능한 접근 제어를 위해 스마트 컨트렉트를 사용하고자 한다. 이를 위해 IoT 데이터 공유를 위하여 탱글 네트워크 환경에서 실행되는 스마트 컨트렉트(Smart Contract)를 사용한 IoT 서비스 접근 제어를 설계하였다. 본 연구를 통해 이기종의 다양한 사물인터넷 서비스들이 탱글 네트워크를 통해 스마트 컨트렉트를 공유함으로써, 중앙 제어 없이 IoT 데이터 접근이 안전하게 이루어 질 수 있다.

Smart contract-based personal information management (스마트 컨트랙트 기반 개인정보 관리권한 연구)

  • Baek YeongTae;Min Youn A
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2024.01a
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    • pp.445-447
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    • 2024
  • 스마트 디바이스 등 디지털 환경의 변화가 가속화되며 온라인을 통한 개인정보 관리에 대한 관심이 높아지고 있다. 개인정보를 다루는 플랫폼마다 다양한 개인정보 접속 가능자가 존재하며 블록체인 기반 스마트 컨트랙트를 이용하여 개인정보의 관리권한에 대한 유연한 관리 및 개인정보 관리 이력을 투명하게 관리할 수 있다. 본 논문을 통하여 블록체인 기술의 스마트 컨트랙트 기반 데이터 사용 및 관리권한에 대한 규칙을 설정하고 유연하게 수정하여 개인정보를 안전하고 투명하게 관리할 수 있다.

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