Publications related to Random oracle

On Quantum Secure Compressing Pseudorandom Functions

In this paper we characterize all 2n-bit-to-n-bit Pseudorandom Functions (PRFs) constructed with the minimum number of calls to n-bit-to-n-bit PRFs and arbitrary number of linear functions. First, we show that all two-round constructions are either classic ...

2023

Security in the Presence of Quantum Adversaries

Khashayar Barooti

With the looming threat of large-scale quantum computers, a fair portion of recent cryptographic research has focused on examining cryptographic primitives from the perspective of a quantum adversary. Shor's 1994 result revealed that quantum computers can ...

EPFL2023

On Succinct Non-interactive Arguments in Relativized Worlds

Alessandro Chiesa

Succinct non-interactive arguments of knowledge (SNARKs) are cryptographic proofs with strong efficiency properties. Applications of SNARKs often involve proving computations that include the SNARK verifier, a technique called recursive composition. Unfort ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

Zero-Knowledge IOPs with Linear-Time Prover and Polylogarithmic-Time Verifier

Alessandro Chiesa, Siqi Liu

Interactive oracle proofs (IOPs) are a multi-round generalization of probabilistically checkable proofs that play a fundamental role in the construction of efficient cryptographic proofs. ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

Analysis of the BIKE post-quantum cryptographic protocols and the Legendre pseudorandom function

Dusan Kostic

The field of post-quantum cryptography studies cryptographic systems that are secure against an adversary in possession of a quantum computer. In 2017, the National Institute of Standards and Technology (NIST) initiated a process to standardize quantum-res ...

EPFL2020

Bidirectional Asynchronous Ratcheted Key Agreement with Linear Complexity

Serge Vaudenay, Fatma Betül Durak

Following up mass surveillance and privacy issues, modern secure communication protocols now seek more security such as forward secrecy and post-compromise security. They cannot rely on an assumption such as synchronization, predictable sender/receiver rol ...

Springer2019

Misuse Attacks on Post-quantum Cryptosystems

Serge Vaudenay, Loïs Evan Huguenin-Dumittan, Abdullah Talayhan, Fatma Betül Durak, Ciprian Baetu

Many post-quantum cryptosystems which have been proposed in the National Institute of Standards and Technology (NISI) standardization process follow the same meta-algorithm, but in different algebras or different encoding methods. They usually propose two ...

SPRINGER INTERNATIONAL PUBLISHING AG2019

On the Security of Two-Round Multi-Signatures

Bryan Alexander Ford, Manu Drijvers, Kasra Edalatnejadkhamene

A multi-signature scheme allows a group of signers to collaboratively sign a message, creating a single signature that convinces a verifier that every individual signer approved the message. The increased interest in technologies to decentralize trust has ...

IEEE Computer Society2019

Seeking Anonymity in an Internet Panopticon

Bryan Alexander Ford

Internet, users often need to assume, by default, that their every statement or action online is monitored and tracked. The Dissent project at Yale University takes a collective approach to online anonymity, based on different algorithmic foundations from ...

2015

HELEN: A Public-Key Cryptosystem Based on the LPN and the Decisional Minimal Distance Problems

Serge Vaudenay, Alexandre Raphaël Duc

We propose HELEN, a code-based public-key cryptosystem whose security is based on the hardness of the Learning from Parity with Noise problem (LPN) and the decisional minimum distance problem. We show that the resulting cryptosystem achieves indistinguisha ...

Springer2013

HELEN: a Public-key Cryptosystem Based on the LPN Problem (Extended Abstract)

Serge Vaudenay, Alexandre Raphaël Duc

We propose HELEN, a new code-based public-key cryptosystem whose security is based on the hardness of the Learning from Parity with Noise problem~(LPN) and the decisional minimum distance problem. We show that the resulting cryptosystem achieves indistingu ...

2012

Resistance against Adaptive Plaintext-Ciphertext Iterated Distinguishers

Serge Vaudenay, Atefeh Mashatan, Asli Bay

Decorrelation Theory deals with general adversaries who are mounting iterated attacks, i.e., attacks in which an adversary is allowed to make d queries in each iteration with the aim of distinguishing a random cipher C from the ideal random cipher C^*. A b ...

2012

A Message Recognition Protocol Based on Standard Assumptions

Serge Vaudenay, Atefeh Mashatan

We look at the problem of designing Message Recognition Protocols (MRP) and note that all proposals available in the literature have relied on security proofs which hold in the random oracle model or are based on non-standard assumptions. Incorporating ran ...

Springer2010

An Analysis of the Blockcipher-Based Hash Functions from PGV

Martijn Stam

Preneel, Govaerts, and Vandewalle (1993) considered the 64 most basic ways to construct a hash function H: {0, 1}*->{0, 1}(n) from a blockcipher E: {0, 1}(n) x {0, 1}(n)->{0,1}(n). They regarded 12 of these 64 schemes as secure, though no proofs or formal ...

Springer Verlag2010

Obfuscation for Cryptographic Purposes

Martijn Stam

Loosely speaking, an obfuscation O of a function f should satisfy two requirements: firstly, using O, it should be possible to evaluate f; secondly, O should not reveal anything about f that cannot be learnt from oracle access to f alone. Several definitio ...

Springer Verlag2010

ARMADILLO: A Multi-purpose Cryptographic Primitive Dedicated to Hardware

Serge Vaudenay, Stéphane Badel, Pouyan Sepehrdad, Nilay Dagtekin, Khaled Ouafi, Jorge Nakahara, Petr Susil

This paper describes and analyzes the security of a general-purpose cryptographic function design, with application in RFID tags and sensor networks. Based on these analyzes, we suggest minimum parameter values for the main components of this cryptographic ...

Springer2010

Secure communication using authenticated channels

Sylvain Pasini

Our main motivation is to design more user-friendly security protocols. Indeed, if the use of the protocol is tedious, most users will not behave correctly and, consequently, security issues occur. An example is the actual behavior of a user in front of an ...

EPFL2009

Quantitative security of block ciphers : designs and cryptanalysis tools

Thomas Baignères

Block ciphers probably figure in the list of the most important cryptographic primitives. Although they are used for many different purposes, their essential goal is to ensure confidentiality. This thesis is concerned by their quantitative security, that i ...

EPFL2008

Mutual Authentication in RFID: Security and Privacy

Serge Vaudenay, Radu-Ioan Paise

In RFID protocols, tags identify and authenticate themselves to readers. At Asiacrypt 2007, Vaudenay studied security and privacy models for these protocols. We extend this model to protocols which offer reader authentication to tags. Whenever corruption i ...

ACM Press2008

Equivalences and calculi for formal verification of cryptographic protocols

Johannes Borgström

Security protocols are essential to the proper functioning of any distributed system running over an insecure network but often have flaws that can be exploited even without breaking the cryptography. Formal cryptography, the assumption that the cryptograp ...

EPFL2008