  Confidentiality in our digital world is based on the security of
cryptographic algorithms. These are usually executed transparently in the
background, with people often relying on them without further knowledge. In the
course of technological progress with quantum computers, the protective
function of common encryption algorithms is threatened. This particularly
affects public-key methods such as RSA and DH based on discrete logarithms and
prime factorization. Our concept describes the transformation of a classical
asymmetric encryption method to a modern complexity class. Thereby the approach
of Cramer-Shoup is put on the new basis of elliptic curves. The system is
provable cryptographically strong, especially against adaptive
chosen-ciphertext attacks. In addition, the new method features small key
lengths, making it suitable for Internet-of-Things. It represents an
intermediate step towards an encryption scheme based on isogeny elliptic
curves. This approach shows a way to a secure encryption scheme for the
post-quantum computing era.
