Posts Tagged ‘pollard’s kangaroo’

Hyperelliptic curve crypto — Dcoder’s keygenme #2

26/09/2011 3 comments

Apparently ordinary elliptic curves in crackmes are getting boring, so Dcoder decided to make things interesting with hyperelliptic curves. Due to intricate nature of HE curves, performing computations on them is more expensive, than for ordinary curves, but on the other hand HE curves provide superior bitstrength security, with regard to size of the base field, they are defined over.

In this blog post, I will try to introduce HE curves, and how to use them in crypto. Using that knowledgle, it will be easy to analyze and break a signature scheme implemented in keygenme #2 by Dcoder. Note that this won’t be a rigorous mathematical dissertation, but a “tutorial” for mathematically inclined programmer :).

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