Opendata, web and dolomites


Teaching Old Crypto New Tricks

Total Cost €


EC-Contrib. €






Project "TOCNeT" data sheet

The following table provides information about the project.


Organization address
address: Am Campus 1
postcode: 3400

contact info
title: n.a.
name: n.a.
surname: n.a.
function: n.a.
email: n.a.
telephone: n.a.
fax: n.a.

 Coordinator Country Austria [AT]
 Project website
 Total cost 1˙882˙244 €
 EC max contribution 1˙882˙244 € (100%)
 Programme 1. H2020-EU.1.1. (EXCELLENT SCIENCE - European Research Council (ERC))
 Code Call ERC-2015-CoG
 Funding Scheme ERC-COG
 Starting year 2016
 Duration (year-month-day) from 2016-04-01   to  2021-03-31


Take a look of project's partnership.

# participants  country  role  EC contrib. [€] 


 Project objective

The bulk of the research in modern cryptography goes into constructing new schemes for which stronger security guarantees can be proven. However, often it is not clear if simple existing schemes already provide the required security, and we just don’t know how to prove it. As these new schemes are usually less efficient, they are not being applied resulting in a large discrepancy between the security that applied schemes are supposed to provide and what is actually proven. This project aims at closing this gap in different contexts: we will revisit simple schemes (including widely deployed ones) using new tools, developed by us and others in the last years, towards proving much stronger security properties than what is currently known. Three research directions in which we have already made substantial progress and which we will further investigate are: Adaptive Security: Often we can prove a scheme secure against selective adversaries, while in practice stronger adaptive security is required. Until recently this was the case for constrained PRFs, the popular LKH multicast encryption and all known proxy re-encryption schemes. Last year we introduced the “nested hybrids” proof technique, which allowed us to prove adaptive security of these schemes. We will further develop and apply this technique. Symmetric Cryptography: Although symmetric schemes are the work horses of crypto, for most of them we only have non-tight security proofs which leave a huge gap to the best known attacks. We recently proved tight security bounds for HMAC (used for authentication in SSL/TLS, SSH and IPsec) and the Sponge family used in the SHA3 standard. Pseudoentropy: Computational notions of entropy have found many applications in the last few years. The tools available to manipulate pseudoentropy yield poor quantitative bounds, resulting in impractical schemes. We will continue our research towards establishing the exact necessary security degradation for manipulating pseudoentropy.


year authors and title journal last update
List of publications.
2018 Hamza Abusalah
Proof Systems for Sustainable Decentralized Cryptocurrencies
published pages: , ISSN: , DOI: 10.15479/at:ista:th_1046
2016 Georg Fuchsbauer, Christian Hanser, Chethan Kamath, Daniel Slamanig
Practical Round-Optimal Blind Signatures in the Standard Model from Weaker Assumptions.
published pages: 391-408, ISSN: , DOI: 10.1007/978-3-319-44618-9_21
2016 Krzysztof Pietrzak, Maciej Skórski
Pseudoentropy: Lower-Bounds for Chain Rules and Transformations.
published pages: 183-203, ISSN: , DOI: 10.1007/978-3-662-53641-4_8
2019 Arka Rai Choudhuri, Pavel Hubacek, Chethan Kamath, Krzysztof Pietrzak and Alon Rosen and Guy N. Rothblum
Finding a Nash Equilibrium Is No Easier Than Breaking Fiat-Shamir
published pages: , ISSN: , DOI: 10.1145/3313276.3316400
2017 Alwen, Joel F; De Rezende, Susanna ; Nordstrom, Jakob ; Vinyals, Marc
Cumulative Space in Black-White Pebbling and Resolution
published pages: , ISSN: , DOI: 10.4230/lipics.itcs.2017.38
2019 Hamza Abusalah, Chethan Kamath, Karen Klein, Krzysztof Pietrzak, Michael Walter
Reversible Proofs of Sequential Work
published pages: , ISSN: , DOI:
2018 Maciej Obremski, Maciej Skórski
Inverted Leftover Hash Lemma
published pages: , ISSN: , DOI:
2018 Joël Alwen, Peter Gaži, Chethan Kamath, Karen Klein, Georg Osang, Krzysztof Pietrzak, Leonid Reyzin, Michal Rolínek, Michal Rybár
On the Memory-Hardness of Data-Independent Password-Hashing Functions
published pages: , ISSN: , DOI:
2017 Abusalah, Hamza; Alwen, Joël; Cohen, Bram; Khilko, Danylo; Pietrzak, Krzysztof; Reyzin, Leonid
Beyond Hellman’s time-memory trade-offs with applications to proofs of space
published pages: , ISSN: , DOI:
2018 Stefan Dziembowski, Krzysztof Pietrzak, Daniel Wichs
Non-Malleable Codes
published pages: , ISSN: , DOI:
2018 Bram Cohen, Krzysztof Pietrzak
Simple Proofs of Sequential Work
published pages: , ISSN: , DOI:
2017 Maciej Skórski
A cryptographic view of regularity lemmas: Simpler unified proofs and refined bounds
published pages: , ISSN: , DOI:
2018 Alwen, Joel; Blocki, Jeremiah; Pietrzak, Krzysztof
Sustained Space Complexity
published pages: , ISSN: , DOI:
4 2020-03-20

Are you the coordinator (or a participant) of this project? Plaese send me more information about the "TOCNET" project.

For instance: the website url (it has not provided by EU-opendata yet), the logo, a more detailed description of the project (in plain text as a rtf file or a word file), some pictures (as picture files, not embedded into any word file), twitter account, linkedin page, etc.

Send me an  email ( and I put them in your project's page as son as possible.

Thanks. And then put a link of this page into your project's website.

The information about "TOCNET" are provided by the European Opendata Portal: CORDIS opendata.

More projects from the same programme (H2020-EU.1.1.)

InsideChromatin (2019)

Towards Realistic Modelling of Nucleosome Organization Inside Functional Chromatin Domains

Read More  

NeuroMag (2019)

The Neurological Basis of the Magnetic Sense

Read More  


The Enemy of the Good: Towards a Theory of Moral Progress

Read More