Which algorithm is considered outdated?

• A. AES
• B. RSA
• C. ECC
• D. DES

Answer: (D)

Understanding which encryption method is considered outdated due to security weaknesses. DES is the older standard that used a 56-bit key, which is far too short for modern security needs. With today's computing power, a brute-force search can recover DES keys in a feasible amount of time, so it no longer provides adequate protection for sensitive data. As a result, DES has been superseded by stronger approaches like Triple DES (which increases the effective key length by applying DES three times) and, most importantly, AES, which uses much larger keys and a modern design. The other options—AES, RSA, and ECC—are all current and widely used for secure encryption and key exchange in contemporary systems, with AES serving as the standard for symmetric encryption and RSA/ECC providing public-key capabilities.