This is a video made for a high school class interested in encryption and security. I sometimes give career talks at high schools, feel free to contact me if your school is near Orange County, CA.
This is a video made for a high school class interested in encryption and security. I sometimes give career talks at high schools, feel free to contact me if your school is near Orange County, CA.
What are the most commonly used encryption techniques, and how do they differ in practice?
Modern systems rely on three major categories of encryption, each used for a different purpose:
1. Symmetric Encryption (AES‑128, AES‑256)
One shared key for encrypting and decrypting.
Extremely fast and ideal for bulk data (files, disks, network traffic).
AES is the current standard because it’s efficient and highly secure.
2. Asymmetric Encryption (RSA, ECC)
Uses a public key to encrypt and a private key to decrypt.
Much slower, so it’s mainly used for key exchange, authentication, and digital signatures.
ECC offers strong security with smaller keys than RSA.
3. Cryptographic Hash Functions (SHA‑256, SHA‑3)
One‑way functions—there’s no decryption step.
Used for integrity checks, password storage, and digital signatures.
How they differ in practice
Symmetric → fast, protects the actual data.
Asymmetric → slower, establishes trust and exchanges keys.
Hashes → verify that data hasn’t been altered.
Most real‑world protocols (like HTTPS) combine all three to get speed, security, and integrity.