Abstract: Smart contracts are computer protocols that facilitate, verify, and execute the negotiation or execution of a contract, or that render a contractual term unnecessary. Blockchain and smart contracts can be used to facilitate almost any financial transaction. Thanks to these smart contracts, the settlement of dividends and coupons could be automated. Smart contracts have become lucrative and profitable targets for attackers because they can hold a great amount of money. Smart contracts, although widely used in blockchain technology, are far from perfect due to security concerns. Although a series of attacks are listed, there is a lack of discussions and proposals on improving security. This survey takes stock of smart contract security from a more comprehensive perspective by correlating the level of vulnerability and systematic review of security levels in smart contracts.
Abstract: Profit and loss sharing suggests an equitable sharing of risks and profits between the parts involved in a financial transaction. Salam is a contract in which advance payment is made for goods to be delivered at a future date. The purpose of this work is to price a new contract for profit and loss sharing based on Salam contract, using Khiyar Al Ghabn which is an agreement of choice in case of misrepresent facts.
Abstract: Due to the rapid growth in modern communication systems, fault tolerance and data security are two important issues in a secure transaction. During the transmission of data between the sender and receiver, errors may occur frequently. Therefore, the sender must re-transmit the data to the receiver in order to correct these errors, which makes the system very feeble. To improve the scalability of the scheme, we present a secure proxy signature scheme with fault tolerance over an efficient and secure authenticated key agreement protocol based on RSA system. Authenticated key agreement protocols have an important role in building a secure communications network between the two parties.
Abstract: Merchants are competing to offer the use of mobile payment to encourage shopping. many mobile payment systems were made available in various locations worldwide; however, they have various drawbacks. This paper proposes a new mobile payment system that discusses the main drawbacks of these systems, namely security and speed of transaction. The proposal is featured by being simple to use by customers and merchants. Furthermore, the proposed system depends on a new authentication factor that is introduced in this paper and called by Two-Factors Authentication Plus, (2FA+).
Abstract: ebXML (Electronic Business using eXtensible
Markup Language) is an e-business standard, sponsored by
UN/CEFACT and OASIS, which enables enterprises to exchange
business messages, conduct trading relationships, communicate
data in common terms and define and register business
processes. While there is tremendous e-business value in the
ebXML, security remains an unsolved problem and one of the
largest barriers to adoption. XML security technologies emerging
recently have extensibility and flexibility suitable for security
implementation such as encryption, digital signature, access
control and authentication.
In this paper, we propose ebXML business transaction models
that allow trading partners to securely exchange XML based
business transactions by employing XML security technologies.
We show how each XML security technology meets the ebXML
standard by constructing the test software and validating messages
between the trading partners.
Abstract: A research study was conducted with an objective to propose a collaborative business strategy of a oil and gas trading company, representing PPT Energy Trading Co., Ltd., with its shareholder, especially electricity and power supply companies for LNG Form of Coal Bed Methane in B2B Transaction. Collaborative business strategy is a strategy to collaborate with other organizations due to have future benefits in both parties, or achieve the business objective through the collaboration of business, its strategy and partners. A structured interview was established to collect the required primary data from the company. Not only interview, but also company’s business plan and annual report were collected and analyzed for the company’s current condition. As the result, this research shows a recommendation to propose a new collaborative strategy with limiting its target market, diversifying product, conducting new business model, and considering other stakeholders.
Abstract: A new approach for timestamp ordering problem in
serializable schedules is presented. Since the number of users using
databases is increasing rapidly, the accuracy and needing high
throughput are main topics in database area. Strict 2PL does not
allow all possible serializable schedules and so does not result high
throughput. The main advantages of the approach are the ability to
enforce the execution of transaction to be recoverable and the high
achievable performance of concurrent execution in central databases.
Comparing to Strict 2PL, the general structure of the algorithm is
simple, free deadlock, and allows executing all possible serializable
schedules which results high throughput. Various examples which
include different orders of database operations are discussed.
Abstract: A real time distributed computing has
heterogeneously networked computers to solve a single problem. So
coordination of activities among computers is a complex task and
deadlines make more complex. The performances depend on many
factors such as traffic workloads, database system architecture,
underlying processors, disks speeds, etc. Simulation study have been
performed to analyze the performance under different transaction
scheduling: different workloads, arrival rate, priority policies,
altering slack factors and Preemptive Policy. The performance metric
of the experiments is missed percent that is the percentage of
transaction that the system is unable to complete. The throughput of
the system is depends on the arrival rate of transaction. The
performance can be enhanced with altering the slack factor value.
Working on slack value for the transaction can helps to avoid some
of transactions from killing or aborts. Under the Preemptive Policy,
many extra executions of new transactions can be carried out.