Is it incorrect to say "Many important algorithms in public-key cryptosystems used at present have their security based on the assumption that the Discrete Logarithm Problem (DLP) over some chosen finite groups has no efficient solution. The groups taken for currently used cryptosystems, that are considered to have intractable DLP are, $\mathbb{Z}_n^{*}$ and cyclic subgroups of elliptic curves over finite fields $\mathbb{Z}_p$." $p$ is a prime and $n$ will be a product of two primes $pq$.
If there is an error in the above statement please kindly explain me.
Thank you in advance.
