Encryption is the process of transforming readable data (plaintext) into an unreadable format (ciphertext) using a mathematical algorithm and a key. Only someone with the correct decryption key can convert it back to its original form.
There are two main types of encryption. Symmetric encryption uses the same key to both encrypt and decrypt data. AES (Advanced Encryption Standard) is the most widely used symmetric algorithm. It is fast and efficient, which makes it the go-to choice for encrypting data at rest (stored files, database fields) and data in transit (when wrapped by TLS).
Asymmetric encryption (also called public-key cryptography) uses a pair of keys: a public key that anyone can use to encrypt a message, and a private key that only the recipient holds to decrypt it. RSA and elliptic curve cryptography are common asymmetric algorithms. This approach solves the key distribution problem, since you can share your public key openly without compromising security.
In practice, most secure communication uses both. When you visit an HTTPS website, your browser and the server perform a TLS handshake that uses asymmetric encryption to exchange a temporary symmetric key. All subsequent data flows using that faster symmetric key. Bitcoin wallets also rely on asymmetric cryptography: your private key signs transactions, and the network verifies them using your public key.
Encryption is the foundation of online security. Without it, passwords, financial data, and private messages would travel across the internet as readable text. For crypto users, encryption protects wallet access and transaction integrity. For developers, understanding encryption helps you make sound decisions about data storage, API security, and compliance requirements.
The Cyber Threats panel on the TerminalFeed dashboard tracks active malware campaigns and indicators of compromise, many of which target encrypted communication channels. Our browser console guide also touches on how your browser handles encrypted connections behind the scenes.