The fast progress of quantum computing is a serious threat to classical cryptographic schemes like RSA and elliptic curve cryptography, and it is time to come up with safe post-quantum schemes. One of the new solutions is isogeny-based cryptography which has attracted attention because of its good-security basis and comparatively small key sizes. Nevertheless, currently used post-quantum cryptographic (PQC) designs, such as lattice-based and code-based ones, are typically characterized by the high key sizes, high computational costs, or scaling issues, with the necessity to have a well-balanced and efficient cryptographic design. This paper presents a powerful isogeny-based cryptosystem, which can allow safe communication in the post-quantum context. The mathematical complexity of isogenies over supersingular elliptic curves forms the foundation of the proposed framework and it has a structured architecture comprising of parameterization, key generation, encryption/decryption and communication layers. The design of the optimization of algorithms to generate keys, exchange keys securely and encrypt messages using shared secret derivation mechanisms is part of the methodology. Security analysis is also carried out to assess the resistance to quantum attacks and against known cryptanalytic vulnerabilities. The metrics used to conduct performance evaluation are computed cost, key size, and latency, and the results are compared to typical PQC schemes, like lattice-based (Kyber) and code-based (McEliece) systems. The results show that the model proposed has much smaller key sizes (330 bytes public key) with moderate computational efficiency although a little bit more latency than lattice-based methods.