An instructor is contrasting encryption and hashing while explaining how organisations protect data. Which TWO statements about encryption and hashing are correct? Select TWO.
- AEncryption is a one-way transformation that, like hashing, cannot be reversed even by a party holding the correct key.
- BHashing converts data into a fixed-length value that is not designed to be reversed back to the input. Correct
- CEncryption in transit protects data as it moves across a network, for example between a client and a service. Correct
- DHashing keeps a secret key so that the original value can be recovered whenever it is later needed.
- EEncryption at rest only applies to data held in memory and never to data stored on a disk.
Why A is wrong: Tempting because both scramble data, but encryption is reversible by design: the correct key decrypts the ciphertext back to the original value, which is exactly what separates it from one-way hashing.
Why B is correct: Hashing is one-way and yields a fixed-length digest, so it cannot be reversed to recover the original input.
Why C is correct: Encryption in transit secures data while it travels over a network so intercepted traffic stays unreadable.
Why D is wrong: Tempting because keys feel central, but hashing uses no decryption key and is not reversible like encryption.
Why E is wrong: This reverses the meaning; encryption at rest protects stored data on persistent media, not data in memory.