Hash: The family $\cal L$ is 2-universal, not 1-universal

06-hash/hash.tex

@@ -134,7 +134,7 @@ ${\cal L} = \{ h_{a,b} \mid a,b\in [p] \}$ from $[p]$ to $[m]$, where
 $h_{a,b}(x) = ((ax+b) \bmod p) \bmod m$.
 }
 
-\theorem{The family~$\cal L$ is 1-universal.}
+\theorem{The family~$\cal L$ is 2-universal.}
 
 \proof
 Let $x,y$ be two distinct numbers in $[p]$.