{c}

This is natural question because both <integer factorization> and <discrete logarithm> are the basis for the most popular <public-key cryptography> systems as of 2020 (<RSA (cryptosystem)> and <Diffie-Hellman key exchange> respectively), and both are <NP-intermediate>. Why not use something more provenly hard?
* https://cs.stackexchange.com/questions/356/why-hasnt-there-been-an-encryption-algorithm-that-is-based-on-the-known-np-hard "Why hasn't there been an encryption algorithm that is based on the known NP-Hard problems?"


Discussion on "NP-hard cryptosystems" by Ciro Santilli 32