Weak-Key Classes attaks on IDEA algo

[akimp3]

Hi,

I am searching attaks that work on the IDEA (complete 8 round) algorithm. I have found a paper entitled:New Weak-Key Classes of IDEA
by Alex Biryukov, Jorge Nakahara Jr, Bart Preneel, Joos Vandewalle.
I am familiar with the IDEA algo because I have implemented it in C as a part of my homework.
the problem is that I dont understand the Boomerang attak.
Here is the paper:
h++p://www.cosic.esat.kuleuven.be/publications/article-189.pdf
On page 4:
what is a differential pattern?
what is the definition of the reversed DELTA sign?
Is there anyone familiar with this attak who could explain it to me?

Thanks in advance

Akimp3

[mike]

You ought to read the original paper by David Wagner.

http://www.cs.berkeley.edu/~daw/papers/boomerang-fse99.ps
slides
http://www.cs.berkeley.edu/~daw/papers/boomerang-fse99-slides.ps

And also Kelsey/Kohno/Schneier's paper turning it into a chosen-plaintext attack.

http://www.cse.ucsd.edu/users/tkohno/papers/FSE00/

[mike]

PS if you still don't get it after reading those, let me know and I'll try to help.

[akimp3]

Hi

Thank you very much for your help. I will read those papers and contact you if I dont undersatand them.

Best Regards

Akimp3