scholarly journals Infochain: A Decentralized, Trustless and Transparent Oracle on Blockchain

2020 ◽  
Author(s):  
Naman Goel ◽  
Cyril van Schreven ◽  
Aris Filos-Ratsikas ◽  
Boi Faltings
Keyword(s):  
System Design ◽  
Empirical Analysis ◽  
Real World ◽  
Third Party ◽  
The Real ◽  
Design And Implementation ◽  
Correct Information ◽  
Financial Transactions ◽  
First Time ◽  
Implementation Challenge

Blockchain based systems allow various kinds of financial transactions to be executed in a decentralized manner. However, these systems often rely on a trusted third party (oracle) to get correct information about the real-world events, which trigger the financial transactions. In this paper, we identify two biggest challenges in building decentralized, trustless and transparent oracles. The first challenge is acquiring correct information about the real-world events without relying on a trusted information provider. We show how a peer-consistency incentive mechanism can be used to acquire truthful information from an untrusted and self-interested crowd, even when the crowd has outside incentives to provide wrong informations. The second is a system design and implementation challenge. For the first time, we show how to implement a trustless and transparent oracle in Ethereum. We discuss various non-trivial issues that arise in implementing peer-consistency mechanisms in Ethereum, suggest several optimizations to reduce gas cost and provide empirical analysis.

A Database Project in a Small Company (or How the Real World Doesn't Always Follow the Book)

2009 ◽  
pp. 468-483
Author(s):  
Efrem Mallach
Keyword(s):  
Information Retrieval ◽  
Real World ◽  
Retrieval System ◽  
Information Retrieval System ◽  
Small Company ◽  
The Real ◽  
Design And Implementation ◽  
Development Methods

The case study describes a small consulting company’s experience in the design and implementation of a database and associated information retrieval system. Their choices are explained within the context of the firm’s needs and constraints. Issues associated with development methods are discussed, along with problems that arose from not following proper development disciplines.

Tow Monitoring System Design for the Real World

1985 ◽  
Author(s):  
C.R. Campman ◽  
F.W. Debord
Keyword(s):  
System Design ◽  
Monitoring System ◽  
Real World ◽  
The Real

scholarly journals Chosen-Key Distinguishers on 12-Round Feistel-SP and 11-Round Collision Attacks on Its Hashing Modes

2016 ◽  
pp. 13-32
Author(s):  
Xiaoyang Dong ◽  
Xiaoyun Wang
Keyword(s):  
Time Use ◽  
Real World ◽  
Degrees Of Freedom ◽  
Block Cipher ◽  
The Other ◽  
Compression Function ◽  
The Real ◽  
Collision Attacks ◽  
First Time ◽  
Model Affect

Since Knudsen and Rijmen proposed the known-key attacks in ASIACRYPT 2007, the open-key model becomes more and more popular. As the other component of the open-key model, chosen-key model was applied to the full attacks on AES-256 by Biryukov et al. in CRYPTO 2009. In this paper, we explore how practically the chosen-key model affect the real-world cryptography and show that 11-round generic Feistel-SP block cipher is no longer safe in its hashing modes (MMO and MP mode) as there exist collision attacks. This work improves Sasaki and Yasuda’s collision attacks by 2 rounds with two interesting techniques. First, we for the first time use the available degrees of freedom in the key to reduce the complexity of the inbound phase, which extends the previous 5-round inbound differential to a 7-round one. This results in a 12-round chosen-key distinguisher of Feistel-SP block cipher. Second, inspired by the idea of Wang et al., we construct collisions using two blocks. The rebound attack is used in the second compression function. We carefully balance the freedom of the first block and the complexity of the rebound attack, and extend the chosen-key attack to a 11-round collision attack on its hashing modes (MMO and MP mode).

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