In short
Symmetric encryption uses the same secret key to encrypt and decrypt data. It is fast, so it is used to protect large volumes of data, but the key must be shared securely between the parties.
Key takeaways
- The Advanced Encryption Standard (AES) is the most widely used symmetric algorithm.
- Secure web connections use asymmetric encryption to exchange a symmetric session key, then symmetric encryption for the data.
- Anyone who obtains the key can read the data, so key management is critical.
Where it's tested
ISC: Information Security Fundamentals — study notes, a five-minute revision sheet and practice questions.
Practise: 3 questions
Question 1 of 3 · 0 answered
Asymmetric encryption differs from symmetric encryption in that asymmetric encryption: