With the widespread use of the internet, there is a need to secure the communication channel through Cyber-Physical Systems as they carry essential information, for which we rely upon various cryptographic algorithms. With the advancement of Quantum Computers, security-related public-key encryption methods would become ineffective. Furthermore, the critical research areas for ensuring security against quantum attacks are Quantum Cryptography and Post Quantum techniques, such as Lattice-Based Cryptography, Code-Based Techniques, Hash-based and Multivariate-based techniques. One of the best techniques is Lattice-based cryptography, which provides security against Quantum attacks through its unique, light weighted, and complex security properties that can be used effectively to secure the Fog-cloud network. This paper deals with key generation and digital signature algorithms based on Ring Learning with Error using Lattice-based schemes. The proposed Lattice-based Quantum Advanced Encryption Standard method provides less time for encryption, decryption, and validation of signatures along with distinct keys. The maximum encryption and decryption time for the message is 34.1 μsecond and 0.0280 second, respectively. The quantum bit required for the encryption and decryption of text is between 10 to 21.