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PeertoPeer Based Resource Discovery in Global Grids: A Tutorial
, 2007
"... Efficient Resource discovery mechanism is one of the fundamental requirement for Grid computing systems, as it aids in resource management and scheduling of applications. Resource discovery activity involve searching for the appropriate resource types that match the user’s application requirements. ..."
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Efficient Resource discovery mechanism is one of the fundamental requirement for Grid computing systems, as it aids in resource management and scheduling of applications. Resource discovery activity involve searching for the appropriate resource types that match the user’s application requirements. Various kinds of solutions to grid resource discovery have been suggested, including the centralised and hierarchical information server approach. However, both of these approaches have serious limitations in regards to scalability, faulttolerance and network congestion. To overcome these limitations, indexing resource information using a decentralised (such as PeertoPeer (P2P)) network model has been actively proposed in the past few years. This article investigates various decentralised resource discovery techniques primarily driven by P2P network model. To summarise, this article presents a: (i) summary of current state of art in grid resource discovery; (ii) resource taxonomy with focus on computational grid paradigm; (iii) P2P taxonomy with focus on extending the current structured systems (such as Distributed Hash Tables) for indexing ddimensional grid resource queries 1; (iv) detailed survey of existing works that can support ddimensional grid resource queries; and (v) classification of the surveyed approaches based on the proposed P2P taxonomy. We believe that this taxonomy and its mapping to relevant systems would be useful for academic and industry based researchers who are engaged in the design of scalable Grid and P2P systems. 1
Design principles for dedicated hash functions
 LECTURE NOTES IN THE COMPUTER JOURNAL, 2007 COMPUTER SCIENCE
, 1994
"... Dedicated hash functions are cryptographically secure compression functions which are designed specifically for hashing. They intend to form a practical alternative for hash functions based on another cryptographic primitive like a block cipher or modular squaring. About a dozen of dedicated hash ..."
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Dedicated hash functions are cryptographically secure compression functions which are designed specifically for hashing. They intend to form a practical alternative for hash functions based on another cryptographic primitive like a block cipher or modular squaring. About a dozen of dedicated hash functions have been proposed in the literature. This paper discusses the design principles on which these hash functions are based.
A study on peertopeer based discovery of grid resource information
, 2006
"... Efficient Resource discovery mechanism is one of the fundamental requirement for Grid computing systems, as it aids in resource management and scheduling of applications. Resource discovery activity involve searching for the appropriate resource types that match the user’s application requirements. ..."
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Cited by 2 (2 self)
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Efficient Resource discovery mechanism is one of the fundamental requirement for Grid computing systems, as it aids in resource management and scheduling of applications. Resource discovery activity involve searching for the appropriate resource types that match the user’s application requirements. Various kinds of solutions to grid resource discovery have been suggested, including the centralised and hierarchical information server approach. However, both of these approaches have serious limitations in regards to scalability, faulttolerance and network congestion. To overcome these limitations, indexing resource information using a decentralised (such as PeertoPeer (P2P)) network model has been actively proposed in the past few years. This article investigates various decentralised resource discovery techniques primarily driven by P2P network model. To summarise, this article presents a: (i) summary of current state of art in grid resource discovery; (ii) resource taxonomy with focus on computational grid paradigm; (iii) P2P taxonomy with focus on extending the current structured systems (such as Distributed Hash Tables) for indexing ddimensional grid resource queries; (iv) detailed survey of existing works that can support ddimensional grid resource queries; and (v) classification of the surveyed approaches based on the proposed P2P taxonomy. We believe that this taxonomy and its mapping to relevant systems would be useful for academic and industry based researchers who are engaged in the design of scalable Grid and P2P systems. 1
Domain Extender for Collision Resistant Hash Functions Using a Directed Acyclic Graph
, 2003
"... We study the problem of securely extending the domain of a collision resistant compression function. Our rst contribution is to show that given an arbitrary directed acyclic graph and a collision resistant compression function, it is possible to construct a collision resistant hash function. Nex ..."
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We study the problem of securely extending the domain of a collision resistant compression function. Our rst contribution is to show that given an arbitrary directed acyclic graph and a collision resistant compression function, it is possible to construct a collision resistant hash function. Next we introduce a new technique for constructing a hash function which can handle arbitrary length strings. The amount of padding and the number of invocations of the compression function required by our algorithm is asymptotically smaller compared to the MerkleDamgard algorithm. Our third contribution is to provide some concrete examples and hence derive the foundation for the design of a secure parallel hash algorithm.
Construction of UOWHF: Tree Hashing Revisited
, 2002
"... We present a binary tree based parallel algorithm for extending the domain of a UOWHF. The key length expansion is 2m bits for t = 2; m(t+1) bits for 3 t 6 and m(t+blog 2 (t 1)c) bits for t 7, where m is the length of the message digest and t 2 is the height of the binary tree. The previously be ..."
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We present a binary tree based parallel algorithm for extending the domain of a UOWHF. The key length expansion is 2m bits for t = 2; m(t+1) bits for 3 t 6 and m(t+blog 2 (t 1)c) bits for t 7, where m is the length of the message digest and t 2 is the height of the binary tree. The previously best known binary tree algorithm required a key length expansion of m 2(t 1) bits. We also obtain the lower bound that any binary tree based algorithm must make a key length expansion of 2m bits if t = 2 and a key length expansion of m (t + 1) bits for t 3. Hence for 2 t 6 our algorithm makes optimal key length expansion and for practical sized processor trees the key length expansion is close to the lower bound.
An Investigation of the Enhanced Target Collision Resistance Property for Hash Functions
 CRYPTOLOGY EPRINT ARCHIVE, REPORT 2009/506
, 2009
"... We revisit the enhanced target collision resistance (eTCR) property as a newly emerged notion of security for dedicatedkey hash functions, which has been put forth by Halevi and Krawczyk at CRYPTO’06, in conjunction with the Randomized Hashing mode to achieve this property. Our contribution is tw ..."
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We revisit the enhanced target collision resistance (eTCR) property as a newly emerged notion of security for dedicatedkey hash functions, which has been put forth by Halevi and Krawczyk at CRYPTO’06, in conjunction with the Randomized Hashing mode to achieve this property. Our contribution is twofold. Firstly, we provide a full picture of the relationships between eTCR and each of the seven security properties for a dedicatedkey hash function, considered by Rogaway and Shrimpton at FSE’04; namely, collision resistance (CR), the three variants of secondpreimage resistance (Sec, aSec, eSec) and the three variants of preimage resistance (Pre, aPre, ePre). The results show that, for an arbitrary dedicatedkey hash function, eTCR is not implied by any of these seven properties, and it can only imply three of the properties; namely, eSec (TCR), Sec, Pre. In the second part of the paper, we analyze the eTCR preservation capabilities of several domain extension transforms (a.k.a. modes of operation) for hash functions, including (Plain, Strengthened, and Prefixfree) MerkleDamg˚ard, Randomized Hashing, Shoup, Enveloped Shoup, XOR Linear Hash (XLH), and Linear Hash (LH). From this analysis it turns out that, with the exception of a nested variant of LH, none of the investigated transforms can preserve the eTCR property.
On the security of multivariate hash functions
"... Abstract Multivariate hash functions are a type of hash functions whose compression function is explicitly defined as a sequence of multivariate equations. Olivier Billet etc. have designed the hash function MQHASH and Jintai Ding etc. also propose a similar construction, which the security depends ..."
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Abstract Multivariate hash functions are a type of hash functions whose compression function is explicitly defined as a sequence of multivariate equations. Olivier Billet etc. have designed the hash function MQHASH and Jintai Ding etc. also propose a similar construction, which the security depends on the difficulty of solving randomly drawn systems of multivariate equations over a finite field. Finding preimage and collision can be reduced to solve the multivariate equations, which is a well known NPhard problem. To prove the security of MQHASH, the designer assume that a multivariate hash function is a pseudorandom number generator. In this paper, we analyze the security of multivariate hash functions and conclude that low degree multivariate functions such as MQHASH are neither pseudorandom nor unpredictable. There may be trivial collisions and fixed point attacks if the parameter of the compression function has been chosen. And they are also not computationresistance, which makes MAC forgery easily.
Edon–R, An Infinite Family of Cryptographic Hash Functions
, 2006
"... We propose a new infinite family of cryptographic hash functions, Edon–R, based on a recently defined candidate oneway function. Edon–R is a class of hash functions with variable output lengths. It is defined using quasigroups and quasigroup string transformations. ..."
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We propose a new infinite family of cryptographic hash functions, Edon–R, based on a recently defined candidate oneway function. Edon–R is a class of hash functions with variable output lengths. It is defined using quasigroups and quasigroup string transformations.
A NonRepudiable Bitstring Commitment Scheme Based on a PublicKey
"... Commitment schemes are building blocks for guaranteeing fairness in higherlevel cryptographic protocols such as mental poker protocols and others. A party Alice commits to a value v (a bit or a bitstring) without revealing it. Alice should not be able to cheat by opening the commitment as v nor t ..."
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Commitment schemes are building blocks for guaranteeing fairness in higherlevel cryptographic protocols such as mental poker protocols and others. A party Alice commits to a value v (a bit or a bitstring) without revealing it. Alice should not be able to cheat by opening the commitment as v nor to deny having committed at all. Most commitment schemes in the literature rely on hash functions, which should be strongly collisionfree for the scheme to be secure. Yet collisionfreeness can only be empirically checked and cannot be met with total certainty. We present a commitment scheme which avoids hash functions by using a publickey cryptosystem instead.
Design of a Predictor for MD5 Based Cryptographic Systems: A TVACPSO Based Approach
"... Abstract This paper puts forward an efficient and optimized method to determine the probablecolluders in a MD5 based cryptosystem. Along with the conventional MD5 implementing architecture, our scheme employs a predictor control block which takes the message stream from the user, and provides the ..."
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Abstract This paper puts forward an efficient and optimized method to determine the probablecolluders in a MD5 based cryptosystem. Along with the conventional MD5 implementing architecture, our scheme employs a predictor control block which takes the message stream from the user, and provides the loglist of the equal length bitstreams that are most likely to produce collisions with the message stream in a real time system. The predictor controller uses Time varying Acceleration Coefficient Particle Swarm optimization (TVACPSO) algorithm. Besides proposing the algorithm itself, the paper also surveys the performance of the predictor when employed with different hardware platforms. Key words: MD5, collision, TVACPSO 1