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A Stamped Hidden-signature Scheme Utilizing The Elliptic Curve Discrete Logarithm Problem

Mohamed M. Nasreldin Rasslan
2011 International Journal of Network Security  
This is under the assumption that the signer has to perform the signing process on the same day and that she is free to sign at any time that day.  ...  The hidden blind signature application deals with message anonymity only and cannot be done through a strong blind signature; the notary service is one example of a hidden blind signature.  ...  One variant of these computational Diffie-Hellman problem is the Inverse Computational Diffie-Hellman assumption.  ... 
dblp:journals/ijnsec/Rasslan11 fatcat:aynl3l55wbfgdf4546bwfuqcja

Cryptanalysis of a Pseudorandom Generator Based on Braid Groups [chapter]

Rosario Gennaro, Daniele Micciancio
2002 Lecture Notes in Computer Science  
Our attack immediately applies to the pseudo-random generator and synthesizer proposed by the same authors based on the decisional Ko-Lee assumption, and shows that neither of them is cryptographically  ...  We show that the decisional version of the Ko-Lee assumption for braid groups put forward by Lee, Lee and Hahn at Crypto 2001 is false, by giving an efficient algorithm that solves (with high probability  ...  A preliminary version of this attack was presented at the rump session of Crypto 2001 [7] . We would like to thank E. Lee and S.G.  ... 
doi:10.1007/3-540-46035-7_1 fatcat:4fysn7e3sbbqnnxri6g4zcef3u

Learning with Errors in the Exponent [chapter]

Özgür Dagdelen, Sebastian Gajek, Florian Göpfert
2016 Lecture Notes in Computer Science  
We initiate the study of a novel class of group-theoretic intractability problems.  ...  We give the very first construction of a semantically secure public-key encryption system in the standard model.  ...  Acknowledgements The authors would like to thank Steven Galbraith and Dan Bernstein to point to a bug in a previous version of the paper, and the attendees of the Cryptography Workshop in Oberwolfach for  ... 
doi:10.1007/978-3-319-30840-1_5 fatcat:7i25r2bn6bdgphr3lzqj64zmxq

Interactive Diffie-Hellman Assumptions with Applications to Password-Based Authentication [chapter]

Michel Abdalla, David Pointcheval
2005 Lecture Notes in Computer Science  
The proof of security is in the random oracle model and is based on new and apparently stronger variants of the decisional Diffie-Hellman problem which are of independent interest.  ...  In this paper, we introduce a new three-party password-based authenticated key exchange protocol based on the two-party encrypted key exchange of Bellovin and Merritt.  ...  By applying the splitting lemma on the product probability space Ω 1 × Ω 1 , where Ω 1 = {(ω 1 , P, X, r 0 , r 1 )} and Ω 1 = {(ω 2 , k, b)}, one can show that there exists a subset S 1 of Ω 1 with probability  ... 
doi:10.1007/11507840_31 fatcat:ckqqntc5cfgopocarasl5usk5e

Using Hash Functions as a Hedge against Chosen Ciphertext Attack [chapter]

Victor Shoup
2000 Lecture Notes in Computer Science  
Although this is a reasonable intractability assumption, it would be preferable to base a security proof on a weaker assumption, such as the Computational Diffie-Hellman assumption.  ...  The cryptosystem recently proposed by Cramer and Shoup [CS98] is a practical public key cryptosystem that is secure against adaptive chosen ciphertext attack provided the Decisional Diffie-Hellman assumption  ...  Recently, Cramer and Shoup [CS98] presented a practical cryptosystem and proved its security in the standard model, based on the Decisional Diffie-Hellman (DDH) assumption.  ... 
doi:10.1007/3-540-45539-6_19 fatcat:qpfkgh6kpfegvhdwcdisxbdoza

Simple oblivious transfer protocols compatible with Kummer and supersingular isogenies [article]

Vanessa Vitse
2018 IACR Cryptology ePrint Archive  
In this article, we propose a new simple oblivious transfer (OT) protocol, based on the Diffie-Hellman key exchange, that only uses exponentiations; we also revisit the older Wu-Zhang-Wang scheme.  ...  The semantic security of our proposals relies on the hardness of non-standard versions of the (supersingular) Diffie-Hellman problem, that are investigated within this article.  ...  This one-way function can be used to construct a Diffie-Hellman-type key exchange.  ... 
dblp:journals/iacr/Vitse18 fatcat:ledr3zpjqvbkvlmtstn6b4tu5i

Formal security proof for a scheme on a topological network

Roberto Civino, Riccardo Longo
2021 Advances in Mathematics of Communications  
Recently, Aragona et al. proposed a new cryptographic scheme, ECTAKS, which provides a solution to this design problem by means of a Diffie-Hellman-like key establishment protocol based on elliptic curves  ...  and on a prime field.  ...  On the basis of the Computational and Decisional Diffie-Hellman assumptions [2, 3] , we develop a security model for ECTAKS and we prove that the scheme is secure against key-recovery and key-indistinguishability  ... 
doi:10.3934/amc.2021009 fatcat:35mwiffwpbdprf2xi2v6y62su4

The Group of Signed Quadratic Residues and Applications [chapter]

Dennis Hofheinz, Eike Kiltz
2009 Lecture Notes in Computer Science  
That is, in this group the Diffie-Hellman problem is hard, even in the presence of a Decisional Diffie-Hellman oracle.  ...  We are able to show that under the factoring assumption, the Strong Diffie-Hellman assumption over the signed quadratic residues holds.  ...  The Strong Diffie-Hellman (SDH) problem [1] is to compute DH g (X, Y ) from g, X, Y while having access to a (Decisional) DH oracle that returns 1 on input (Ŷ ,Ẑ) if DH g (X,Ŷ ) =Ẑ and (Ŷ ,Ẑ) ∈ G × G  ... 
doi:10.1007/978-3-642-03356-8_37 fatcat:5j7bx5g6jfejtngcbngeuskpc4

An Algebraic Framework for Diffie-Hellman Assumptions [chapter]

Alex Escala, Gottfried Herold, Eike Kiltz, Carla Ràfols, Jorge Villar
2013 Lecture Notes in Computer Science  
We put forward a new algebraic framework to generalize and analyze Diffie-Hellman like Decisional Assumptions which allows us to argue about security and applications by considering only algebraic properties  ...  To illustrate the conceptual advantages of our algebraic framework, we construct several fundamental primitives based on any MDDH-Assumption.  ...  Introduction Arguably, one of the most important cryptographic hardness assumptions is the Decisional Diffie-Hellman (DDH) Assumption.  ... 
doi:10.1007/978-3-642-40084-1_8 fatcat:hfxawdare5honfwdajgxxmfcsy

An Efficient Scheme for Proving a Shuffle [chapter]

Jun Furukawa, Kazue Sako
2001 Lecture Notes in Computer Science  
In this paper, we propose a novel and efficient protocol for proving the correctness of a shuffle, without leaking how the shuffle was performed.  ...  The proposed protocol will be a building block of an efficient, universally verifiable mix-net, whose application to voting system is prominent.  ...  decisional Diffie-Hellman problem.  ... 
doi:10.1007/3-540-44647-8_22 fatcat:7olfv3f7fvc2xc63lxolrycicu

A Simple Threshold Authenticated Key Exchange from Short Secrets [chapter]

Michel Abdalla, Olivier Chevassut, Pierre-Alain Fouque, David Pointcheval
2005 Lecture Notes in Computer Science  
An authentication server can indeed be seen as two distinct entities, namely a gateway (which is the direct interlocutor of the client) and a back-end server (which is the only one able to check the identity  ...  The authentication server, on the other hand, is assumed to know the password.  ...  Acknowledgements The authors would like to thank Raymond Choo for pointing out a flaw in a previous version of our schemes that made them susceptible to attacks by corrupted gateways.  ... 
doi:10.1007/11593447_31 fatcat:rblad7olofdh7ekrvezphm5z5q

Public Traceability in Traitor Tracing Schemes [chapter]

Hervé Chabanne, Duong Hieu Phan, David Pointcheval
2005 Lecture Notes in Computer Science  
For our scheme, we provide a complete proof, based on new computational assumptions, related to the bilinear Diffie-Hellman ones, in the standard model.  ...  If such a collusion happens, at least one member of the latter collusion will be detected.  ...  MDDH -the mixed decisional Diffie-Hellman problem: Given (P, aP, a 2 P, g b , Z) for some a, b ∈ Z q and Z ∈ G 2 , where g =ê(P, P ), output yes if Z = g ba 2 and no otherwise.  ... 
doi:10.1007/11426639_32 fatcat:cnj4wqxijrca5i3ff6rij5oere

SoK: The Problem Landscape of SIDH [article]

David Urbanik, David Jao
2018 IACR Cryptology ePrint Archive  
problem and the computational and decisional Diffie-Hellman problems.  ...  As in the case of ordinary Diffie-Hellman, one is interested in knowing if these problems are related.  ...  In ordinary Diffie-Hellman on a cyclic group G generated by д, the decisional Diffie-Hellman problem is to determine whether a triple (x, y, z) ∈ G × G × G satisfies log д (x) log д (y) = log д (z) modulo  ... 
dblp:journals/iacr/UrbanikJ18 fatcat:xkkozh7vcveapkxt4arssbbika


David Urbanik, David Jao
2018 Proceedings of the 5th ACM on ASIA Public-Key Cryptography Workshop - APKC '18  
problem and the computational and decisional Diffie-Hellman problems.  ...  As in the case of ordinary Diffie-Hellman, one is interested in knowing if these problems are related.  ...  In ordinary Diffie-Hellman on a cyclic group G generated by д, the decisional Diffie-Hellman problem is to determine whether a triple (x, y, z) ∈ G × G × G satisfies log д (x) log д (y) = log д (z) modulo  ... 
doi:10.1145/3197507.3197516 dblp:conf/ccs/UrbanikJ18 fatcat:4rfngowkojaqbd2koitqw72c7u

Universally Convertible Directed Signatures [chapter]

Fabien Laguillaumie, Pascal Paillier, Damien Vergnaud
2005 Lecture Notes in Computer Science  
Our construction relies on the so-called xyz-trick applicable to bilinear map groups.  ...  We define proper security notions for UCDS schemes and show that our construction is secure in the random oracle model, under computational assumptions close to the CDH and DDH assumptions.  ...  It is then possible to obtain invisibility under the Decisional Tripartite Diffie-Hellman assumption.  ... 
doi:10.1007/11593447_37 fatcat:kpucfvpoafdn5o2iv4wiwrjs4e
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