Simple PKE schemes from the TSPEM problem

In the quantum era, the advent of quantum computers poses significant threats to the security of current cryptosystems. Therefore, designing quantum-resistant cryptoschemes becomes important to guarantee information security. This work concentrates on the development of the post-quantum public key encryption (PKE) scheme. Non-commutative cryptography (NCC) has entered the field of post-quantum cryptography. We utilize the TSPEM problem with asymmetric structures (which serve as a potential candiate for resisting quantum attacks) to construct two PKE schemes which are demonstrated to be CPA security under the DTSPEM assumption. By representing the plaintext as a matrix, these schemes can effectively encrypt a significant amount of information in a single operation. Assuming an equal amount of messages for encryption, the proposed schemes acheive superior efficiency compared to existing PKE schemes. Structurally, our systems exhibit a level of synchronization and coexistence due to the distinct public keys $(P)$ and ciphertexts $(C_1)$. The efficiency analysis is conducted by comparing known schemes from the aspect of specific cryptographic indicators. Generally, the proposed ones offer several advantages including provable security, high efficiency, potential quantum-resistant, and relative ease of implementation; along with synchronization and coexistence. Our investigation has established the feasibility of constructing PKE schemes based on the TSPEM problem, specifically for asymmetric communication scenarios. The preliminary results pave the way for further exploration of the TSPEM problem ${}^{\prime }$s potential in developing other cryptosystems suitable for quantum computing environments.