What is applied cryptography?

Applied cryptography is the practical application of cryptographic techniques and security mechanisms to achieve real-world security goals. It involves using cryptographic algorithms (like encryption, hashing, digital signatures) and protocols to protect data confidentiality, integrity, authenticity, and non-repudiation in various systems and applications. Common uses include securing communications (e.g., TLS/SSL for HTTPS), protecting stored data (e.g., encryption at rest), verifying software integrity (e.g., code signing), and enabling secure transactions (e.g., digital signatures for contracts).