Symmetric and asymmetric encryption
One shared key versus a public/private key pair.
Symmetric encryption uses one secret key for both encrypting and decrypting: it is fast, but the key must be shared securely. Asymmetric encryption uses a key pair: data encrypted with the recipient’s public key can only be decrypted with their private key. In practice, asymmetric encryption is used to exchange a symmetric key, which then encrypts the data.
On the exam
For confidentiality, encrypt with the recipient’s public key. For a digital signature, the sender uses their own private key.
Related terms
- Digital signatureProof of who sent a message and that it wasn’t changed.
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