What is symmetric encryption?
D5 · Crypto · CompTIA Security+ SY0-701Symmetric encryption uses a single shared key for both encrypting and decrypting data. Both the sender and receiver must possess the same secret key.
Common algorithms: AES (128/192/256-bit — current gold standard), 3DES (deprecated), ChaCha20 (used in TLS 1.3).
Key challenge: key distribution — how do you securely share the key? Solved by using asymmetric encryption to exchange the symmetric key (hybrid encryption).
Common algorithms: AES (128/192/256-bit — current gold standard), 3DES (deprecated), ChaCha20 (used in TLS 1.3).
Key challenge: key distribution — how do you securely share the key? Solved by using asymmetric encryption to exchange the symmetric key (hybrid encryption).
Symmetric = fast, used for bulk data (disk encryption, TLS session data). AES-256 is the exam-safe answer for "strongest symmetric algorithm." Key management is the main weakness — if the key is compromised, everything is.