CompTIA CySA+ Practice Test

Which cipher suite should NOT be used with OpenSSL?

1. DES

2. AES

3. RSA

4. ECC

The correct answer is: DES

The recommendation against using DES (Data Encryption Standard) with OpenSSL stems from its known vulnerabilities and inadequate key length. DES utilizes a fixed key size of 56 bits, which has been deemed insufficient to withstand modern computational power and cryptanalysis techniques. The security landscape has evolved, and DES is now considered obsolete, with significant weaknesses that make it susceptible to brute-force attacks. In contrast, AES (Advanced Encryption Standard) and RSA (Rivest-Shamir-Adleman), along with ECC (Elliptic Curve Cryptography), are strong and widely accepted algorithms in cryptographic practices. AES uses variable key lengths (128, 192, or 256 bits), providing robust security. RSA is a widely used public-key cryptographic method, and ECC offers the same level of security as RSA but with shorter key lengths, making it more efficient. Since the contemporary standards prioritize security and efficiency, the use of DES is discouraged in modern cryptographic implementations, especially when alternatives like AES, RSA, and ECC provide much more robust protection.