Given an Elliptic curve over $\mathbb Z_n$ is it $\#P$ hard to compute 1. $\# E(\mathbb Z_n)$? I doubt the problem is $PP$-hard since it seems unlikely $\# E(\mathbb Z_n)\leq\frac n2$ is exceeded. Nevertheless is it $\oplus P$ hard to compute 2. $\# E(\mathbb Z_n)\bmod 2$? 3. $a\bmod 2$ where $2^a|\# E(\mathbb Z_n)$ and $2^{a+1}\nmid\# E(\mathbb Z_n)$?