The paper is concerned with the necessity of new cryptographic systems on classical assumptions and the issue of the secure, quantum resistant communication systems. It suggests a cryptography scheme based on modular forms and exploitation of the transformation invariance, Fourier structure and L-functions to generate strong keys and encrypt. It has been experimentally demonstrated that the performance is best with shorter encryption time (6.7 ms), decryption time (7.4 ms) and protection strength (192 bits) that is better than RSA and ECC. The novelty is that it is a combination of deep number-theoretic features and real world cryptography. It has a contribution of one mathematical-cryptographic framework. The plan proposes efficient and post quantum secure applications that are scalable in the existing digital communications systems.