[HGI-News-de] CASA Distinguished Lecture: Monday, 18/05/2020, 1.00 pm: Joan Daemen

Fr Mai 15 15:17:55 CEST 2020

Dear all,

this Monday, 18/05/2020, 1.00 pm: Joan Daemen will be our first speaker 
for the CASA Distinguished Lectures.
Zoom Webinar: https://us02web.zoom.us/j/86909824055

Joan Daemen (Radboud University Nijmegen): On deck functions

Abstract. Modern symmetric encryption and/or authentication schemes 
consist of modes of block ciphers. Often these schemes have a proof of 
security on the condition that the underlying block cipher is PRP or 
SPRP-secure: keyed with a fixed and unknown key it shall be hard to 
distinguish from a random permutation. The PRP and SPRP security notions 
have become so accepted that they are referred to as the standard model. 
(S)PRP security cannot be proven but thanks to this nice split in 
primitives and modes, the assurance of block-cipher based cryptographic 
schemes relies on public scrutiny of the block cipher in the simple 
standard scenario.

Security proofs of modes can become quite complicated and errors have 
been made. This complexity can be reduced if we add an input to the 
block cipher, a so-called tweak. The resulting primitive is called a 
tweakable block cipher and its (S)PRP security is tweakable (S)PRP. The 
presence of the tweak makes these primitives more costly for the same 
target security strength due to the increase in degrees of freedom for 
the adversary.Another approach is to abandon block ciphers altogether 
and replace them by permutations.

During the last decade a field of permutation-based cryptography has 
appeared that defines modes on top of these primitives and many new 
permutations are proposed. At their core these modes often have a 
duplex-like construction and its parallel nephew, farfalle. However, 
while it is reasonable to assume one can build a block cipher that is 
(S)PRP secure it is impossible to formalize what it means for a 
permutation to behave like an ideal permutation. We show that 
permutation-based crypto can have its own standard model with (keyed) 
duplex functions or farfalle-based functions at their center, both 
instances of what we call deck functions and the standard model is the 
pseudorandom function (PRF) security of deck functions.

Modes can be defined in terms of deck functions and can be proven secure 
in the setting where the keyed deck function is hard to distinguish from 
a random oracle. The PRF security of the deck function is the subjec of 
public scrutiny.In this talk I will discuss some modes on top of deck 
functions and some concrete deck functions.

Bio. After graduating in electromechanical engineering Joan Daemen was 
awarded his PhD in 1995 from KU Leuven. After his contract ended at 
COSIC, he privately continued his crypto research and contacted Vincent 
Rijmen to continue their collaboration that would lead to the Rijndael 
block cipher, and this was selected by NIST as the new Advanced 
Encryption Standard in 2000. After over 20 years of security industry 
experience, including work as a security architect and cryptographer for 
STMicroelectronics, he is now a professor in the Digital Security Group 
at Radboud University Nijmegen.

He co-designed the Keccak cryptographic hash function thate was selected 
as the SHA-3 hash standard by NIST in 2012 and is one of the founders of 
the permutation-based cryptography movement and co-inventor of the 
sponge, duplex and farfalle constructions. In 2017 he won the Levchin 
Prize for Real World Cryptography and in 2020 the RSA award for 
excellence in mathematics. In 2018 he was awarded an ERC advanced grant 
called ESCADA and an NWO TOP grant called SCALAR, both for design and 
analysis of symmetric crypto

This is a public event. Please feel free to forward the invitation.

All information about the Distinguished Lectures, our speakers and the 
Zoom Webinar links can be found here:

https://casa.rub.de/en/news/distinguished-lectures

You are all invited to be part of that. A registration is not necessary.

If you would like to be informed about further Distinguished Lectures, 
please send an e-mail to info at casa.rub.de and we will keep you up to 
date.

Beste Grüße / Best regards

---------------------------------------------

CASA Team

RUHR-UNIVERSITÄT BOCHUM

Horst Görtz Institut für IT-Sicherheit (HGI) / Exzellenzcluster CASA

ID 2 – PO Box 31

Universitätsstr. 150

44780 Bochum, Germany

Tel: +49-(0)234-32-27722

E-Mail: info at casa.ruhr-uni-bochum.de

www.hgi.rub.de

www.casa.rub.de

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Dear all,

we are happy to announce, that our CASA Distinguished Lectures Series 
will continue this semester.

Due to COVID-19, the lectures will be held online - and will, therefore, 
be accessible to people all over the world.

In our CASA Distinguished Lectures, we welcome selected international 
and national scientists at the Horst Görtz Institute for IT Security 
(HGI) in Bochum, Germany. The lectures of these influential and 
pioneering guest speakers, usually lasting one hour, are always followed 
by a discussion with the participants.

Our goal is to encourage discussions and open up new perspectives within 
the field of cybersecurity research.

This is a public event. Please feel free to forward the invitation.

Our confirmed speakers until now:
Monday, 18/05/2020, 1.00 pm: Joan Daemen (Radboud University Nijmegen)
Friday, 29/05/2020, 1.30 pm: Andreas Zeller (CISPA Helmholtz Center for 
Information Security)
Wednesday, 10/06/2020, 10.15 am: Battista Biggio (PRA Lab, University of 
Cagliari)

more to follow ...

All information about the Distinguished Lectures, our speakers and the 
Zoom Webinar links can be found here:

https://casa.rub.de/en/news/distinguished-lectures

You are all invited to be part of that. A registration is not necessary.

If you would like to be informed about further Distinguished Lectures, 
please send an e-mail to info at casa.rub.de and we will keep you up to 
date.

Beste Grüße / Best regards

---------------------------------------------

CASA Team

RUHR-UNIVERSITÄT BOCHUM

Horst Görtz Institut für IT-Sicherheit (HGI) / Exzellenzcluster CASA

ID 2 – PO Box 31

Universitätsstr. 150

44780 Bochum, Germany

Tel: +49-(0)234-32-27722

E-Mail: info at casa.ruhr-uni-bochum.de

www.hgi.rub.de

www.casa.rub.de