Joux’s multicollision attack is one of the most striking results on hash functions and also one of the simplest: it computes a k-collision on iterated hashes in time ⌈log2 k⌉ · 2 , whereas k! · 2 was thought to be optimal. Kelsey and Schneier improved this to 3 · 2 if storage 2 is available and if the compression functions admits easily found fixed-points. This paper presents a simple technique...

Calculating the mean physical stock in a simple periodic review inventory system seems to be straightforward. However, the standard approximate expressions appear to yield inaccurate results, especially for low service levels. Low service levels are frequently encountered at intermediate nodes in cost-optimal solutions for multiechelon systems. In this note, we present an improved approximate m...

Social media has found its place in the digital economy. Social media tools offer easy, interactive and cost-efficient possibilities to interact with various stakeholders. Not only the mere availability of social media tools but also their implementation renders benefits to an organization. Consequently, evidence from practice indicates that social media is an appropriate way to establish stake...

Infrastructure-as-a-Service is the most flexible form of cloud computing and provides great opportunities to acquire and release computing resources as necessary. However, consumers face an increasingly opaque market due to growing number of providers and tariff options. As an approach to aid consumers finding the right tariff matching their needs, we suggest a broker model as an intermediate b...

Abstract: The highly competitive communications markets of the future should encompass mechanisms for enabling users to find and associate with the most appropriate retailers, i.e., those offering at a certain time period, adequate quality services in a cost efficient manner. This paper presents such mechanisms. Our starting point is the definition of a business case, through which the role of ...

In the future, electronic exchanges will be a major facilitator of negotiation systems and a driver for new forms of bargaining and matchmaking between potential trading partners. Most existing bargaining systems are based on formalized auction schemes which need a centralized authority (an auctioneer). With the development of decentralized networks, we need new forms of electronic bargaining w...

During the past four decades, public trust in governments has continued to diminish due to various administrative, political, socio-cultural, economic, and mass media causes. Focusing on the administrative dimension, this study explores selected administrative factors to the declining of public trust, including public perception of administrative corruption (lack of transparency), inefficiency ...

The efficient and economic allocation of resources is one main goal in the field of production planning and control. Nowadays, a new variable gains in importance throughout the planning process: Energy. Energy-efficiency has already been widely discussed in literature, but with a strong focus on reducing the overall amount of energy used in production. This paper provides a brief systematic app...

Analyzing Cost Efficient Production Behavior Under Economies of Scope: A Nonparametric Methodology In designing a production model for firms that generate multiple outputs, we take as a starting point that such multi-output production refers to economies of scope, which in turn originate from joint input use and input externalities. We provide a nonparametric characterization of cost efficient ...