How does cryptography work in an online MCA?

Cryptography protects information using mathematical techniques such as encryption, hashing and digital signatures. MCA students should understand the purpose and correct use of these mechanisms rather than treating them as just formulas. For an MCA learner, the best way to understand cryptography is to connect the theory with a small working example. This point is specifically relevant to the cryptography aspect of MCA study. For this specific question about cryptography, the practical takeaway is to relate the concept to your own MCA learning goal. In other words, this guidance addresses: How does cryptography work in an online MCA?