What describes decryption?

What describes decryption?

• A. The process of encrypting data to protect its contents
• B. The undoing of encryption to data using a decryption key
• C. The hashing of data to verify integrity
• D. The signing of data to ensure authenticity

Answer: (B)

Decryption is the process of reversing encryption to recover the original data. Encryption turns plaintext into ciphertext using a key, making it unreadable to anyone without the right key. Decryption applies the corresponding decryption operation and key to that ciphertext to restore the original plaintext. In symmetric systems, the same key encrypts and decrypts; in asymmetric systems, the recipient uses their private key (or the appropriate private/public pair) to decrypt data that was encrypted with the public key. This is different from hashing, which is a one-way function for integrity, and from signing, which provides authenticity but isn’t used to recover the original data. So the description that says you undo encryption using a decryption key best captures what decryption is.

Decryption is the process of reversing encryption to recover the original data. Encryption turns plaintext into ciphertext using a key, making it unreadable to anyone without the right key. Decryption applies the corresponding decryption operation and key to that ciphertext to restore the original plaintext. In symmetric systems, the same key encrypts and decrypts; in asymmetric systems, the recipient uses their private key (or the appropriate private/public pair) to decrypt data that was encrypted with the public key. This is different from hashing, which is a one-way function for integrity, and from signing, which provides authenticity but isn’t used to recover the original data. So the description that says you undo encryption using a decryption key best captures what decryption is.