[HGI-News-de] Maximizing Small Root Bounds by Linearization and Applications to Small Secret Exponent RSA von Mathias Herrmann

[Newsletter des Horst Görtz Instituts]

Hallo,

im Rahmen des HGI Kolloquiums "Aktuelle Themen der IT-Sicherheit" wird am kommenden *Donnerstag* der folgende Vortrag angeboten:

Mathias Herrmann (CITS)
*Maximizing Small Root Bounds by Linearization and Applications to Small Secret Exponent RSA*

Termin: Donnerstag, den 20. Mai um  11.00 Uhr (*s.t.*)
Raum: IC 4/161

Abstract: We present an elementary method to construct optimized lattices that are used for finding small roots of polynomial equations. Former methods first construct some large lattice in a generic way from a polynomial $f$ and then optimize via finding suitable smaller dimensional sublattices. In contrast, our method focuses on optimizing $f$ first which then directly leads to an optimized small
dimensional lattice. Using our method, we construct the first elementary proof of the Boneh-Durfee
attack for small RSA secret exponents with $d \leq N^{0.292}$. Moreover, we identify a sublattice structure behind the Jochemsz-May attack for small CRT-RSA exponents $d_p, d_q \leq N^{0.073}$. Unfortunately, in contrast to the Boneh-Durfee attack, for the Jochemsz-May attack the sublattice does not help to improve the bound asymptotically. Instead, we are able to attack much large values of $d_q,d_q$ in practice by LLL reducing smaller dimensional lattices.

Interessierte sind herzlich eingeladen!


Vorankündigung: 
27. Mai 2010: Orr Dunkelman (The Weizmann Institute of Science), A Practical-Time Attack on the KASUMI Cryptosystem Used in GSM and 3G Telephony - 10. Juni 2010: Markus Kasper (EMSEC), Title TBA - 17. Juni 2010: Roberto Avanzi (RUB), Arithmetic of Supersingular Koblitz Curves in Characteristic Three - 24. Juni 2010: Christopher Wolf (AG Long Term Security), Äquivalente Schlüssel in Multivariaten Quadratischen Systemen - 1. Juli: Juraj Somorovsky (NDS), Streaming-based verification of XML Signatures in SOAP Messages - 15. Juli 2010: Alexander Meurer(CITS), Correcting Errors in RSA Private Keys.


Im Laufe des Semesters gibt es noch freie Termine im HGI Kolloquium - Freiwillige vor!


Informationen über die nächsten geplanten Vorträge im Rahmen des HGI Kolloquiums sind auch im Web zu finden:
http://www.hgi.rub.de/hgi/hgi-seminar/aktuelles


Viele Grüße
Timo