Cryptography is the study and practice of securing information through mathematical techniques. It includes methods for encrypting data, verifying identities, ensuring message integrity, and generating secure keys. Modern cryptography underpins technologies like HTTPS, JWT signatures, and password hashing. Algorithms such as AES, RSA, and SHA are used to protect data in transit and at rest.
Why it matters
Cryptography makes secure communication possible on the internet. Without strong cryptographic tools, attackers could read private messages, impersonate users, or alter data unnoticed. Developers rely on cryptography when implementing login systems, secure tokens, and data protection features.
Examples
Using TLS certificates to enable HTTPS, hashing a password before storing it in a database, or signing a session token are all examples of cryptographic operations. Lessons such as HTTPS and Why It Matters explain how cryptography secures web traffic.