Which encryption standard is more secure?

Which encryption standard is more secure?

• A. DES
• B. AES
• C. RC4
• D. 3DES

Answer: (B)

Security strength here hinges on key length, block size, and resistance to known attacks. DES uses only a 56-bit key, so a brute-force search with today’s hardware can break it relatively quickly, making it insecure. ThreeDES increases the effective key length (to 112 or 168 bits) but it still operates on a 64-bit block and is slower; its block size also introduces vulnerabilities for long messages, and it’s not considered future-proof. RC4 is a stream cipher with known biases in its keystream, and practical attacks in modern protocols have shown weaknesses that undermine its security. AES, however, supports much larger keys (128, 192, or 256 bits) and a 128-bit block, built on a robust design that resists known cryptanalytic attacks while delivering strong performance in both hardware and software. For these reasons, AES is the most secure choice among the options.

Security strength here hinges on key length, block size, and resistance to known attacks. DES uses only a 56-bit key, so a brute-force search with today’s hardware can break it relatively quickly, making it insecure. ThreeDES increases the effective key length (to 112 or 168 bits) but it still operates on a 64-bit block and is slower; its block size also introduces vulnerabilities for long messages, and it’s not considered future-proof. RC4 is a stream cipher with known biases in its keystream, and practical attacks in modern protocols have shown weaknesses that undermine its security. AES, however, supports much larger keys (128, 192, or 256 bits) and a 128-bit block, built on a robust design that resists known cryptanalytic attacks while delivering strong performance in both hardware and software. For these reasons, AES is the most secure choice among the options.