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. When preparing for an IT role, be ready to explain how cryptography works and where you would use it in a real application. 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.