A comprehensive study on lattice, code, and hash-based cryptographic algorithms in post-quantum security with practical applications

A computer is recognized as a universal device that can simulate any other computational device, though it may take time. Cryptography is becoming more important as the Internet becomes more popular. When shopping online or using Internet banking, safe communication is crucial. However, traditional cryptography often relies on certain computational challenges, such as the RSA system, which is because of the complexity of factoring integers. This makes it vulnerable to advances in hardware, algorithms, and quantum techniques such as the Shor algorithm. In today's digital world, secure communication is essential. Quantum physics can change traditional cryptography. For example, an eavesdropper like Eve could record 2014 messages and, with future technology, decrypt them. Distribution of quantum keys (QKD) is a key application of quantum cryptography and promises unconditional communication security, unlike traditional methods that depend on unproven computational assumptions. Instead, QKD focuses on the physical laws. A challenge is the secure distribution of this key. In traditional methods, trusted couriers may be compromised unknowingly. QKD, introduced by Bennett and Brassard in 1984, involves Alice sending Bob photons with different polarization. They share their measurement results through a secure channel and generate a key while checking for interference. The onetime pad protocol ensures complete security if the key is not reused. QKD has become advanced enough for practical use. The article discusses cutting edge encryption methods including Lattice, Hash and Code-Based Cryptography, and their uses.