In Antonella's privacy scenario, what type of encryption is being used?

In Antonella's privacy scenario, what type of encryption is being used?

• A. Asymmetric encryption
• B. Hashing
• C. Digital signature
• D. Symmetric encryption

Answer: (D)

The main idea here is confidentiality with a shared secret. Symmetric encryption uses the same secret key to both lock (encrypt) and unlock (decrypt) the data. If Antonella and the intended recipient share a single secret key and that key stays secret, anyone who doesn’t have the key can’t read the message, which is exactly what privacy requires. This is different from hashing, which isn’t reversible and isn’t used to hide data but to verify integrity. It’s also different from a digital signature, which uses a private key to prove who authored a message and to ensure it hasn’t been altered, not to keep the content secret. And it’s different from asymmetric encryption, which uses a public/private key pair—good for scenarios where you can’t share a secret key in advance but is typically slower for large data and is not about maintaining a shared secret for ongoing privacy. So, when the scenario centers on protecting content with a single shared key that both sender and receiver use, symmetric encryption is the best fit.

The main idea here is confidentiality with a shared secret. Symmetric encryption uses the same secret key to both lock (encrypt) and unlock (decrypt) the data. If Antonella and the intended recipient share a single secret key and that key stays secret, anyone who doesn’t have the key can’t read the message, which is exactly what privacy requires.

This is different from hashing, which isn’t reversible and isn’t used to hide data but to verify integrity. It’s also different from a digital signature, which uses a private key to prove who authored a message and to ensure it hasn’t been altered, not to keep the content secret. And it’s different from asymmetric encryption, which uses a public/private key pair—good for scenarios where you can’t share a secret key in advance but is typically slower for large data and is not about maintaining a shared secret for ongoing privacy.

So, when the scenario centers on protecting content with a single shared key that both sender and receiver use, symmetric encryption is the best fit.