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197
Keying hash functions for message authentication
, 1996
"... The use of cryptographic hash functions like MD5 or SHA for message authentication has become a standard approach inmanyInternet applications and protocols. Though very easy to implement, these mechanisms are usually based on ad hoc techniques that lack a sound security analysis. We present new cons ..."
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Cited by 503 (39 self)
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The use of cryptographic hash functions like MD5 or SHA for message authentication has become a standard approach inmanyInternet applications and protocols. Though very easy to implement, these mechanisms are usually based on ad hoc techniques that lack a sound security analysis. We present new constructions of message authentication schemes based on a cryptographic hash function. Our schemes, NMAC and HMAC, are proven to be secure as long as the underlying hash function has some reasonable cryptographic strengths. Moreover we show, in a quantitativeway, that the schemes retain almost all the security of the underlying hash function. In addition our schemes are e cient and practical. Their performance is essentially that of the underlying hash function. Moreover they use the hash function (or its compression function) as a black box, so that widely available library code or hardware can be used to implement them in a simple way, and replaceability of the underlying hash function is easily supported.
Reasoning about Belief in Cryptographic Protocols
 Proceedings 1990 IEEE Symposium on Research in Security and Privacy
, 1990
"... Abstract. Analysis methods for cryptographic protocols have often focused on information leakage rather than on seeing whether a protocol meets its goals. Many protocols, however, fall far short of meeting their goals, sometimes for quite subtle reasons. We introduce a mechanism for reasoning about ..."
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Cited by 207 (6 self)
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Abstract. Analysis methods for cryptographic protocols have often focused on information leakage rather than on seeing whether a protocol meets its goals. Many protocols, however, fall far short of meeting their goals, sometimes for quite subtle reasons. We introduce a mechanism for reasoning about belief as a systematic way to understand the working of cryptographic protocols. Our mechanism captures more features of such protocols than that given in a recent work [1], to which our proposals are a substantial extension. 1 Introduction Solutions to computer security problems over the last few years have brought forth the need for rigorous analysis methods. Formal tools must be provided to determine whether a solution indeed solves a problem, as well as to enable comparisons between proposed solutions. In this paper we propose a method for reasoning about cryptographic protocols in a distributed environment. The work described was inspired by the recent development of a modal logic to ...
Pseudorandom functions revisited: The cascade construction and its concrete security
 Proceedings of the 37th Symposium on Foundations of Computer Science, IEEE
, 1996
"... Abstract Pseudorandom function families are a powerful cryptographic primitive, yielding, in particular, simple solutions for the main problems in private key cryptography. Their existence based on general assumptions (namely, the existence of oneway functions) has been established.In this work we ..."
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Cited by 96 (21 self)
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Abstract Pseudorandom function families are a powerful cryptographic primitive, yielding, in particular, simple solutions for the main problems in private key cryptography. Their existence based on general assumptions (namely, the existence of oneway functions) has been established.In this work we investigate new ways of designing pseudorandom function families. The goal is to find constructions that are both efficient and secure, and thus eventually to bring thebenefits of pseudorandom functions to practice.
Cryptographic HashFunction Basics: Definitions, Implications, and Separations for Preimage Resistance, SecondPreimage Resistance, and Collision Resistance
, 2004
"... We consider basic notions of security for cryptographic hash functions: collision resistance, preimage resistance, and secondpreimage resistance. We give seven di#erent definitions that correspond to these three underlying ideas, and then we work out all of the implications and separations among ..."
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Cited by 83 (3 self)
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We consider basic notions of security for cryptographic hash functions: collision resistance, preimage resistance, and secondpreimage resistance. We give seven di#erent definitions that correspond to these three underlying ideas, and then we work out all of the implications and separations among these seven definitions within the concretesecurity, provablesecurity framework.
MultiPropertyPreserving Hash Domain Extension and the EMD Transform
 Advances in Cryptology – ASIACRYPT 2006
, 2006
"... Abstract We point out that the seemingly strong pseudorandom oracle preserving (PROPr) propertyof hash function domainextension transforms defined and implemented by Coron et. al. [12] can actually weaken our guarantees on the hash function, in particular producing a hash functionthat fails to be ..."
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Cited by 63 (7 self)
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Abstract We point out that the seemingly strong pseudorandom oracle preserving (PROPr) propertyof hash function domainextension transforms defined and implemented by Coron et. al. [12] can actually weaken our guarantees on the hash function, in particular producing a hash functionthat fails to be even collisionresistant (CR) even though the compression function to which the transform is applied is CR. Not only is this true in general, but we show that all the transformspresented in [12] have this weakness. We suggest that the appropriate goal of a domain extension transform for the next generation of hash functions is to be multiproperty preserving, namelythat one should have a single transform that is simultaneously at least collisionresistance preserving, pseudorandom function preserving and PROPr. We present an efficient new transformthat is proven to be multiproperty preserving in this sense.
Hash Functions Based on Block Ciphers
 Proc. of EUROCRYPT 92
, 1993
"... . Iterated hash functions based on block ciphers are treated. Five attacks on an iterated hash function and on its round function are formulated. The wisdom of strengthening such hash functions by constraining the last block of the message to be hashed is stressed. Schemes for constructing mbit ..."
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Cited by 62 (7 self)
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. Iterated hash functions based on block ciphers are treated. Five attacks on an iterated hash function and on its round function are formulated. The wisdom of strengthening such hash functions by constraining the last block of the message to be hashed is stressed. Schemes for constructing mbit and 2mbit hash round functions from mbit block ciphers are studied. A principle is formalized for evaluating the strength of hash round functions, viz., that applying computationally simple #in both directions# invertible transformations to the input and output of a hash round function yields a new hash round function with the same security. By applying this principle, four attacks on three previously proposed 2mbit hash round functions are formulated. Finally, three new hash round functions based on an mbit block cipher with a 2mbit key are proposed. 1 Introduction This paper is intended to provide a rather rounded treatment of hash functions that are obtained by iterati...
Message Authentication using Hash Functions The HMAC Construction
 CryptoBytes
, 1996
"... Introduction Two parties communicating across an insecure channel need a method by which any attempt to modify the information sent by one to the other, or fake its origin, is detected. Most commonly such a mechanism is based on a shared key between the parties, and in this setting is usually calle ..."
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Cited by 50 (1 self)
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Introduction Two parties communicating across an insecure channel need a method by which any attempt to modify the information sent by one to the other, or fake its origin, is detected. Most commonly such a mechanism is based on a shared key between the parties, and in this setting is usually called a MAC, or Message Authentication Code. (Other terms include Integrity Check Value or Cryptographic Checksum). The sender appends to the data D an authentication tag computed as a function of the data and the shared key. At reception, the receiver recomputes the authentication tag on the received message using the shared key, and accepts the data as valid only if this value matches the tag attached to the received message. The most common approach is to construct MACs from block ciphers like DES. Of such constructions Department of Computer Science & Engineering, Mail Code 0114, University of California at San Diego, 9500 Gilman Driv
A composition theorem for universal oneway hash functions
 In Eurocrypt ’00
, 2000
"... Abstract. In this paper we present a new scheme for constructing universal oneway hash functions that hash arbitrarily long messages out of universal oneway hash functions that hash fixedlength messages. The new construction is extremely simple and is also very efficient, yielding shorter keys th ..."
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Cited by 47 (5 self)
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Abstract. In this paper we present a new scheme for constructing universal oneway hash functions that hash arbitrarily long messages out of universal oneway hash functions that hash fixedlength messages. The new construction is extremely simple and is also very efficient, yielding shorter keys than previously proposed composition constructions. 1
Accountable Certificate Management Using Undeniable Attestations
 COMPUTER AND COMMUNICATIONS SECURITY
, 2000
"... This paper initiates a study of accountable certificate management methods, necessary to support longterm authenticity of digital documents. Our main contribution is a model for accountable certificate management, where clients receive attestations confirming inclusion/removal of their certificates ..."
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Cited by 39 (3 self)
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This paper initiates a study of accountable certificate management methods, necessary to support longterm authenticity of digital documents. Our main contribution is a model for accountable certificate management, where clients receive attestations confirming inclusion/removal of their certificates from the database of valid certificates. We explain why accountability depends on the inability of the third parties to create contradictory attestations. After that we define an undeniable attester as a primitive that provides efficient attestation creation, publishing and verification, so that it is intractable to create contradictory attestations. We introduce authenticated search trees and build an efficient undeniable attester upon them. The proposed system is the first accountable longterm certificate management system. Moreover, authenticated search trees can be used in many securitycritical applications instead of the (sorted) hash trees to reduce trust in the authorities, without decrease in efficiency. Therefore, the undeniable attester promises looks like a very useful cryptographic primitive with a wide range of applications.
Limits on the Efficiency of OneWay PermutationBased Hash Functions
 In Proceedings of the 40th Annual IEEE Symposium on Foundations of Computer Science
, 1999
"... Naor and Yung ([NY89]) show that a onebit compressing universal oneway hash function (UOWHF) can be constructed based on a oneway permutation. This construction can be iterated to build a UOWHF which compresses by "n bits, at the cost of "n invocations of the oneway permutation. We sho ..."
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Cited by 30 (0 self)
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Naor and Yung ([NY89]) show that a onebit compressing universal oneway hash function (UOWHF) can be constructed based on a oneway permutation. This construction can be iterated to build a UOWHF which compresses by "n bits, at the cost of "n invocations of the oneway permutation. We show that this construction is not far from optimal, in the following sense: there exists an oracle relative to which there exists a oneway permutation with inversion probability 2 \Gammap(n) (for any p(n) 2 !(log n)), but any construction of an "nbitcompressing UOWHF requires \Omega\Gamma p n=p(n)) invocations of the oneway permutation, on average. (For example, there exists in this relativized world a oneway permutation with inversion probability n \Gamma!(1) , but no UOWHF that invokes it fewer than \Omega\Gamma p n= log n) times.) Thus any proof that a more efficient UOWHF can be derived from a oneway permutation is necessarily nonrelativizing; in particular, no provable construction...