CompTIA Security+ (SY0-501) — Question 133

Which of the following cryptographic algorithms is irreversible?

Answer options

• A. RC4
• B. SHA-256
• C. DES
• D. AES

Correct answer: B

Explanation

SHA-256 is a cryptographic hash function that is designed to be irreversible, meaning you cannot retrieve the original data from the hash. In contrast, RC4, DES, and AES are symmetric encryption algorithms that allow for data to be encrypted and subsequently decrypted back to its original form.