Securing communications with encryption, focusing on SSL/TLS.
Encryption is the process of converting plaintext data into a scrambled, unreadable format called ciphertext. This is the cornerstone of modern data security, ensuring confidentiality. The reverse process is decryption. There are two main types of encryption. Symmetric encryption uses a single, shared secret key for both encryption and decryption. It is very fast and efficient, making it ideal for encrypting large amounts of data. The challenge is securely sharing the secret key between the sender and receiver. Examples include AES and DES. Asymmetric encryption (or public-key cryptography) uses a pair of keys: a public key, which can be shared with anyone, and a private key, which is kept secret. Data encrypted with the public key can only be decrypted with the corresponding private key. This solves the key exchange problem but is much slower than symmetric encryption. Examples include RSA. Transport Layer Security (TLS), the successor to Secure Sockets Layer (SSL), is the protocol that provides security for much of the internet (e.g., HTTPS). TLS uses a combination of both encryption types in a process called a TLS handshake. When a client connects to a server, they use asymmetric encryption (using the server's public key from its SSL certificate) to securely negotiate a shared secret key. Once this shared key is established, they switch to faster symmetric encryption for the actual bulk data transfer. This hybrid approach provides both secure key exchange and efficient data encryption.