Ran Canetti, Oded Goldreich, Silvio Micali.

We introduce the notion of Resettable Zero-Knowledge (rZK),

a new security measure for cryptographic protocols

which strengthens the classical notion of zero-knowledge.

In essence, an rZK protocol is one that remains zero knowledge

even if an adeversary can interact with the prover many times, each

time ...
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Ronald Cramer, Victor Shoup

We present several new and fairly practical public-key encryption

schemes and prove them secure against

adaptive chosen ciphertext attack. One scheme is based on Paillier's

Decision Composite Residuosity (DCR) assumption,

while another is based in the classical Quadratic Residuosity (QR)

assumption. The analysis is in the standard ...
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Jörg Rothe

In this tutorial, selected topics of cryptology and of

computational complexity theory are presented. We give a brief overview

of the history and the foundations of classical cryptography, and then

move on to modern public-key cryptography. Particular attention is

paid to cryptographic protocols and the problem of constructing ...
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Kooshiar Azimian, Javad Mohajeri, Mahmoud Salmasizadeh, Siamak Fayyaz

In this paper, firstly we propose two new concepts concerning the notion of key escrow encryption schemes: provable partiality and independency. Roughly speaking we say that a scheme has provable partiality if existing polynomial time algorithm for recovering the secret knowing escrowed information implies a polynomial time algorithm that can ... more >>>

Kooshiar Azimian

In this paper we compare hardness of two well known problems: the Diffie-Hellman problem and the root finding problem. We prove that in any cyclic group computing Diffie-Hellman is not weaker than root finding if certain circumstances are met. As will be discussed in the paper this theorem can affect ... more >>>

Brett Hemenway, Rafail Ostrovsky

Injective one-way trapdoor functions are one of the most fundamental cryptographic primitives. In this work we give a novel construction of injective trapdoor functions based on oblivious transfer for long strings.

Our main result is to show that any 2-message statistically sender-private semi-honest oblivious transfer (OT) for ...
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Brett Hemenway, Rafail Ostrovsky, Martin Strauss, Mary Wootters

This work considers locally decodable codes in the computationally bounded channel model. The computationally bounded channel model, introduced by Lipton in 1994, views the channel as an adversary which is restricted to polynomial-time computation. Assuming the existence of IND-CPA secure public-key encryption, we present a construction of public-key locally decodable ... more >>>