9618 · 17.1
Encryption, Encryption Protocols and Digital Certificates
Encryption scrambles your data into an unreadable format, protecting it from unauthorised access. Protocols like TLS use this method with digital 'passports' to ensure your online activities, like shopping or banking, are private and secure.
Need to know
What you need to know
- **Symmetric Encryption:** Uses a single, shared secret key for both encryption and decryption. It's very fast and efficient, making it ideal for encrypting large amounts of data. Its main weakness is the 'key distribution problem' – how to securely share the key in the first place.
- **Asymmetric Encryption:** Uses a pair of mathematically linked keys: a public key and a private key. The public key can be shared with anyone and is used for encryption. The private key is kept secret and is the only key that can decrypt the ciphertext. It solves the key distribution problem but is significantly slower than symmetric encryption.
Explanation
Securing Your Digital Post
- Your browser requests a secure connection (HTTPS) from a website's server.
- The server responds by sending its Digital Certificate, which contains its name, details, and its public key.
- Your browser checks if the certificate is valid by contacting the Certificate Authority (CA) that issued it. The CA is like a trusted passport office.
- Once verified, your browser and the server use the public/private keys to securely agree on a temporary, symmetric 'session key' for fast, encrypted communication.