How does hashing differ from encryption?

How does hashing differ from encryption?

• A. Hashing is one-way; encryption is reversible with a key
• B. Hashing is reversible with a key; encryption is one-way
• C. Hashing and encryption are both easily reversible without keys
• D. Hashing always requires a public key

Answer: (A)

Hashing is a one-way transformation that turns input data into a fixed-length digest, and there’s no practical way to recover the original data from that digest. Encryption, on the other hand, converts data into ciphertext with a key, and the original data can be recovered by applying the appropriate decryption key. That fundamental difference—one-way versus reversible with a key—is what separates hashing from encryption. Hashing is commonly used for data integrity and password verification (often with a salt to protect against precomputed attacks), while encryption is used to protect confidentiality, whether data is stored or transmitted. The other statements wrong-fit because hashing does not require a key to be reversible, nor is hashing inherently reversible with a key, and hashing does not require a public key.

Hashing is a one-way transformation that turns input data into a fixed-length digest, and there’s no practical way to recover the original data from that digest. Encryption, on the other hand, converts data into ciphertext with a key, and the original data can be recovered by applying the appropriate decryption key. That fundamental difference—one-way versus reversible with a key—is what separates hashing from encryption.

Hashing is commonly used for data integrity and password verification (often with a salt to protect against precomputed attacks), while encryption is used to protect confidentiality, whether data is stored or transmitted. The other statements wrong-fit because hashing does not require a key to be reversible, nor is hashing inherently reversible with a key, and hashing does not require a public key.