Benne de Weger is universitair docent bij ... / assistant professor at ...

         
   
   

nieuw(s) en hoogtepunten ... / new(s) and highlights ...

Two papers accepted

Chosen-prefx Collisions for MD5 and Applications (with Marc Stevens and Arjen Lenstra), International Journal of Applied Cryptography.
Optimal symmetric Tardos traitor tracing schemes (with Thijs Laarhoven), Designs, Codes and Cryptography.

Comments on Opfer's attempt to prove the Collatz (3n+1) conjecture

My comments on Gerhard Opfer's recent paper on the Collatz (3n+1) conjecture.

Record for the xyz conjecture

The xyz conjecture by Lagarias and Soundararajan states that for coprime positive integer triples x, y, z such that x + y = z, the quality function Q*(x,y,z) = 3/2 (loglog z) / (log P), where P is the largest prime factor of xyz, has lim sup Q* = 1.

The best known value for Q* is 1.63904, from the example 1 + 4374 = 4375.

Here's an updated (November 17, 2011) short report on my further findings, as well as a file with 1731 examples with Q* > 1.4.

I challenge you all to find a better example.

DE SCRYPTION-CODES

(wedstrijd beeindigd per 17 januari 2012)

(helaas is het Scryption begin januari 2011 dicht gegaan)

Rogue CA



Creating a rogue Certification Authority

Boek


Het boek "Elementaire Getaltheorie en Asymmetrische Cryptografie" is verschenen bij Epsilon Uitgaven, juli 2009.
De tweede druk is onlangs uitgekomen...

MCR software


MCR - Modulaire en Cryptografische Rekenmachine
De tweede versie is nu beschikbaar...