**Abstract:** We study the quantum query complexity of finding a collision for a
function f whose outputs are chosen according to a non-uniform
distribution D. We derive some upper bounds and lower bounds
depending on the min-entropy and the collision-entropy of D. In
particular, we improve the previous lower bound in *Targhi, Tabia, Unruh, Quantum Collision-Resistance of Non-Uniformly Distributed Functions, 2016*
from Ω(2^{k/9}) to Ω(2^{k/5}) where k is the min-entropy of D.

**Permalink:** http://www.ut.ee/~unruh/publications/collision2.html