----- Weitergeleitete Nachricht von gkkrypto@exp-math.uni-essen.de ----- Datum: Tue, 2 Nov 2004 14:11:19 +0100 (MEZ) Von: "Graduiertenkolleg Mathematik Ingenieurwiss. Kryptographie" Antwort an: "Graduiertenkolleg Mathematik Ingenieurwiss. Kryptographie" Betreff: Vortragsankündigung (fwd) An: alex.essoh@fernuni-hagen.de, alp.bassa@uni-duisburg-essen.de, arkadius.kalka@ruhr-uni-bochum.de, Biljana Cubaleska , biskup@lothlorien.cs.uni-dortmund.de, blady@exp-math.uni-essen.de, boeckle@exp-math.uni-essen.de, bomke@lmi.ruhr-uni-bochum.de, bouw@exp-math.uni- essen.de, buth@exp-math.uni-essen.de, cpaar@crypto.ruhr-uni-bochum.de, diem@exp- math.uni-essen.de, doerte.rappe@math.uni-dortmund.de, "E. Becker" , Erwin.Rathgeb@exp-math.uni-essen.de, esbold@exp-math.uni-essen.de, esnault@uni-essen.de, firoz.kaderali@fernuni- hagen.de, Frank.Bowert@math.uni-dortmund.de, frank.mueller@lothlorien.cs.uni- dortmund.de, frey@exp-math.uni-essen.de, gerd.steinkamp@fernuni-hagen.de, Gerhard.Rosenberger@mathematik.uni-dortmund.de, hans.dobbertin@ruhr-uni- bochum.de, ina.voigt@mathematik.uni-dortmund.de, jdora@ftk.de, joerg.schwenk@ruhr-uni-bochum.de, Kanat.Abdukhalikov@math.uni-dortmund.de, kay.ruelling@uni-essen.de, kiltz@lmi.ruhr-uni-bochum.de, lange@exp-math.uni- essen.de, ledesma@exp-math.uni-essen.de, li@exp-math.uni-essen.de, Lothar Gerritzen , magiolad@exp-math.uni- essen.de, mat9f0@uni-essen.de, mocenigo@exp-math.uni-essen.de, omar@exp- math.uni-essen.de, oyono@exp-math.uni-essen.de, peter.beelen@uni-essen.de, priplata@exp-math.uni-essen.de, rdc@net.in.tum.de, riebach@exp-math.uni- essen.de, Rudolf Scharlau , simon@lmi.ruhr-uni-bochum.de, stefan.kukulies@uni-essen.de, stichtenoth@uni- essen.de, Suphithat.Songsiri@fernuni-hagen.de, svaba@exp-math.uni-essen.de, Thorsten.Camps@mathematik.uni-dortmund.de, thorsten.kisner@fernuni-hagen.de, trung@exp-math.uni-essen.de, viehweg@uni-essen.de, vinck@exp-math.uni-essen.de, weng@exp-math.uni-essen.de, werner.poguntke@fernuni-hagen.de, wollinger@crypto.ruhr-uni-bochum.de, xavier@exp-math.uni-essen.de ---------- Forwarded message ---------- Date: Tue, 2 Nov 2004 13:55:15 +0100 From: Magnus Daum To: gkkrypto@exp-math.uni-essen.de Subject: [iso-8859-1] Vortragsankündigung ---------------------- Ruhr-Universität Bochum HGI Seminar Kryptographie (Lehrstuhl für Kryptologie und IT-Sicherheit, Prof. Dr. Hans Dobbertin) "Which Hash Functions will survive ?" (Xiaoyun Wang, Shandong University, Xuejia Lai, Shanghai Jiaotong University, Magnus Daum, Ruhr University Bochum) Freitag, 5.November 2004, 14.15 Uhr in NA 01/99 Hash functions are an important primitive in many cryptographical applications, for example in digital signature schemes, where instead of a message its short hash value is signed. In practical implementations hash functions have to be fast and secure. The latter means, that it is impossible to find so- called "collisions", i.e. pairs of different messages with the same hash value. However, presently no method is known to prove the security of hash functions. As in case of block ciphers for instance, their design in practice follows more an adhoc approach. In reality, with only very few exceptions, hash functions of the MD4 family are applied. Recently there has been great progress in the analysis of these hash functions. At Crypto 2004 rump session in Santa Barbara, collisions for many hash functions of MD4 type were announced by Xiaoyun Wang, for example for SHA-0, RIPEMD, HAVAL-128, MD5. We are proud to present a talk of Xiaoyun Wang and Xuejia Lai, two cryptographers whose analysis was the most spectacular news at Crypto 2004. A survey of the current situation in the cryptanalysis of hash functions of the MD4 family will be given. It starts with a short introduction on some main aspects and properties of cryptographic hash functions given by Magnus Daum. Then the techniques used by Dobbertin, Chabaud/Joux and Biham/Chen in their respective attacks will be roughly sketched. Finally Wang and Lai will describe ideas and methods they used in their attack. ----- Ende der weitergeleiteten Nachricht ----- Rita Schröer Ruhr-Universität Bochum Lehrstuhl für Kryptologie und IT-Sicherheit Gebäude NA 5/72 Tel.: +49 234/32-28261 Fax: +49 234/32-14430 e-mail: rita.schroeer@itsc.ruhr-uni-bochum.de