What aspect of elliptic curve encryption paradigms makes them especially susceptible to quantum based attack algorithms? This was a statement made during a talk at today's DFN-CERT conference but unfortunately it wasn't explained further. Can anyone shed light on why elliptic curves are susceptible to quantum based attacks ?
The elliptic curve discrete logarithm—like integer factorization and the classic finite field discrete logarithm—is an instance of the abelian hidden subgroup problem. 

Any abelian (commutative) instance of the hidden subgroup problem can be efficiently solved in quantum computers with (variants of) the Shor algorithm; therefore all of the above problems would be rendered weak if large enough quantum computers were actually built. Here is a concrete polynomial-time quantum attack  for the elliptic curve discrete logarithm. See also this question.