Introduction Application to Lesamnta Application to SHAvite

Charles Bouillaguet

Description

Introduction Application to Lesamnta Application to SHAvite-3512 Attacks on Hash Functions based on Generalized Feistel Application to Lesamnta and SHAvite-3512 Charles Bouillaguet, Orr Dunkelman, Pierre-Alain Fouque, Gaëtan Leurent SAC 2010 – University of Waterloo S T U V S T U V Ki F VUTS VUTS Ki K?i F F G. Leurent (ENS) Attacks on Hash Functions based on Generalized Feistel SAC 2010 1 / 29

• no structural


• hash functions


• valid submissions


• too small


• vuts ki


• hash function


• strength without


• orr dunkelman

Sujets

• Fouqué
• Hash function

Informations

• Publié par: pefav
• Nombre de lectures: 21
• Langue: English

Extrait

Introduction

Application to Lesamnta

Application to SHAvite-3 512

Attacks on Hash Functions based on Generalized Feistel Application to Lesamnta and SHAvite-3 512

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G. Leurent (ENS)

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Charles Bouillaguet, Orr Dunkelman, Pierre-Alain Fouque,Gaëtan Leurent

SAC 2010 – University of Waterloo

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U

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K i

K i K 0 i

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S

F

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Attacks on Hash Functions based on Generalized Feistel

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SAC 2010

1 / 29

Introduction

I

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Application to Lesamnta

Hash Functions

A public function with no structural properties. I Cryptographic strength without keys!

F:{0,1}

∗ → {0,1} n

G. Leurent (ENS)

F

Application to SHAvite-3 512

0x1d66ca77ab361c6f

Attacks on Hash Functions based on Generalized Feistel

SAC 2010

2 / 29

Introduction

I

I

Application to Lesamnta

Hash Functions

Apublicfunction withno structural properties. I Cryptographic strength without keys!

F:{0,1}

∗ → {0,1} n

G. Leurent (ENS)

F

Application to SHAvite-3 512

0x1d66ca77ab361c6f

Attacks on Hash Functions based on Generalized Feistel

SAC 2010

2 / 29

Introduction

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I

I I

I I

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Application to Lesamnta

The SHA-3 Competition

Similar to the AES competition Organized by NIST

Application to SHAvite-3 512

Submission dead-line was October 2008: 64 candidiates 51 valid submissions

14 in the second round (July 2009) 5 finalists in September 2010? Winner in 2012?

G. Leurent (ENS)

Attacks on Hash Functions based on Generalized Feistel

SAC 2010

3 / 29

Introduction

Application to Lesamnta

Hash Function Design I Hash function from a block cipher I Davies-Meyer, MMO, ...

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I

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Block cipher from a fixed function I Feistel scheme

Pick your favorite fixed function I AES?

Application to SHAvite-3 512

If the fixed function is too small, use a generalized Feistel: S T U V  S  T  U K i K i K 0 i F F  F

S T U V Lesamntastructure

G. Leurent (ENS)

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S T U V SHAvite-3 512 structure

Attacks on Hash Functions based on Generalized Feistel

SAC 2010

4 / 29