Discussion forum for
Cryptology ePrint Archive reports posted in
2009.
Please put the report number in the subject.
2009/638
Posted by:
addyme (IP Logged)
Date: 02 January 2010 10:33
title: Reducing Elliptic Curve Logarithm to Logarithm in a Finite Field $\mathbb{F}_q$ for Some Orders
The authors are proposing an ingenious method to transform ECDLP to DLP. I was attracted and excited. Anyhow, it seems too good to believe.
Suppose large prime integer $N$ and $#E(F_q)=q+1-t=mN$. ECDLP in $N$-torsion subgroup is considered.
Notice that $q-1|q^2-(t-1)^2$ implies $q-1|mNt$.
Two cases follow:
(1) $N |q-1$, then Tate pairing works for such transformation.
(2) $N \nmid q-1$, then $q-1|mt$, which disables newly proposed algorithm in eprint2009/638.
Unfortunately, it gives no new information than available pairings.