A one-way hash function is an important cryptographic primitive for digital signatures and authentication. Recently much work has been done toward construction of other cryptographic algorithms (e.g., MACs) using hash functions. In particular, such algorithms would be easy to implement with existing codes of hash functions if they are used as a black box without modiication. In this paper we pr...

We propose and investigate the notion of aggregate message authentication codes (MACs) which have the property that multiple MAC tags, computed by (possibly) different senders on multiple (possibly different) messages, can be aggregated into a shorter tag that can still be verified by a recipient who shares a distinct key with each sender. We suggest aggregate MACs as an appropriate tool for au...

Under the Kyoto Protocol the European Union agreed to reduce emissions of greenhouse gases by 8 percent. The Burden-Sharing Agreement (BSA) redistributes the reduction target among the member states. The purpose of this paper is to evaluate the BSA. To determine if cost efficiency was considered, marginal abatement costs (MACs) are first calculated based on an estimation of the directional outp...

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We consider the security of message authentication code (MAC) algorithms, and the construction of MACs from fast hash functions. A new forgery attack applicable to all iterated MAC algorithms is described, the first known such attack requiring fewer operations than exhaustive key search. Existing methods for constructing MACs from hash functions, including the secret prefix, secret suffix, and ...

In this paper, we consider multiuser space-time block codes (STBCs) for 2 × 2 multiple–input multiple–output (MIMO) uplink transmissions. Using a truncated union–bound (UB) approximation, we propose design criteria of multiuser STBCs for quasi-static fading MIMO multiple access channels (MACs). Next, we demonstrate how, by combining the structure of algebraic perfect STBCs in [10], a family of ...

Magnetic cell sorting (MACS) using annexin V-conjugated microbeads eliminates apoptotic spermatozoa based on the externalization of phosphatidylserine residues. The procedure delivers two sperm fractions: annexin V-negative (nonapoptotic) and annexin V-positive (apoptotic). Our aim was to determine whether the sperm fertilizing potential can be improved by selecting a nonapoptotic fraction usin...

Management accounting and control systems (MACS) may be defined as part of the global information system, through which it is collected, processed, analyzed and communicated information (financial and nonfinancial, internal and external) used for planning, monitoring and control of different organizational activities, to optimize the use of resources, to support the process of decision making a...