[HGI-News-de] HGI Seminar Do. 17. Apr: "On Black-Box Ring Extraction and Integer Factorization" by T. Jager

[Newsletter des Horst Görtz Instituts]

Hallo,

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

Tibor Jager (Lehrstuhl für Netz- und Datensicherheit, RUB):
"On Black-Box Ring Extraction and Integer Factorization"

Termin:
Donnerstag, der 17. April um  11.00 Uhr
Raum: IC 4/161.

Alle Interessierte sind herzlich eingeladen!


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Zusammenfassung:

The black-box ring extraction problem has (at least) two important interpretations in the context of cryptography: An efficient algorithm for the black-box ring problem implies the equivalence of computing discrete logarithms and solving the Diffie-Hellman problem. At the same time this implies the inexistence of secure ring-homomorphic encryption schemes. Boneh/Lipton [BL96_BBF] and Maurer/Raub [MR07_BBExtFields] show that there exist subexponential-time algorithms in the case where the black-box ring is a field. It is unknown whether there exist more efficient algorithms.
We provide a polynomial-time reduction from factoring the ring characteristic n to the black-box ring problem for virtually any ring where computation is efficient. 
Under the factoring assumption, this implies the inexistence of efficient generic reductions from computing discrete logarithms to the Diffie-Hellman 
problem. When considered in contrast to [BL96_BBF] and [MR07_BBExtFields], this might be an indicator that secure ring-homomorphic encryption schemes may exist. 

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Informationen über die nächsten geplannten Vorträge im Rahmen des
HGI-Seminars sind auch im Web zu finden:
http://www.hgi.rub.de/deutsch/lehrangebot/seminar/ss2008.html

Gruß,
Biljana Cubaleska