Future Business Leaders of America (FBLA) Cybersecurity Practice Test

Which encryption method utilizes a combination of three keys, each 56 bits in length?

1. AES

2. Triple DES

3. RSA

4. Blowfish

The correct answer is: Triple DES

The encryption method that utilizes a combination of three keys, each 56 bits in length, is Triple DES. This technique enhances the security provided by the original Data Encryption Standard (DES), which uses a single key for encryption. By applying DES three times with three different keys, Triple DES effectively increases the encryption strength. Triple DES operates on blocks of data and improves upon the vulnerabilities of single DES by utilizing the three keys in a specific sequence: the first key encrypts the data, the second key decrypts it, and the third key encrypts it again. This method significantly boosts security, making it much harder to break through brute force attacks, as the effective key length is significantly greater than that of DES alone. Other encryption methods mentioned do not utilize this particular key structure. AES, for example, employs key lengths of 128, 192, or 256 bits, and RSA is based on asymmetric key encryption rather than multiple symmetric keys. Blowfish uses a variable-length key but does not employ the triple key strategy that defines Triple DES. Thus, the distinctive feature of Triple DES being based on three 56-bit keys makes it the correct answer in this context.