CompTIA Network+ Practice Test

Which hashing algorithms are commonly used with the Authentication Header (AH)?

1. SHA-1, SHA-2, and RSA

2. MD5, SHA-1, or SHA-2

3. AES and 3DES

4. Blowfish and Serpent

The correct answer is: MD5, SHA-1, or SHA-2

Hashing algorithms are critical in ensuring data integrity and authenticity, especially within network security protocols like the Authentication Header (AH). The Authentication Header is part of the IPsec suite and is used to provide authentication and integrity for IP packets. The correct choice identifying commonly used hashing algorithms with the Authentication Header includes MD5, SHA-1, and SHA-2. Each of these algorithms serves the function of generating a hash value, which is a fixed-size string of characters that serves as a unique identifier for the original data. This allows the receiving end to confirm that the data has not been tampered with during transit. MD5, while not considered secure against collision attacks, was widely used in the past for its speed and simplicity. SHA-1, which is an improvement over MD5 in terms of security, is also now viewed as weak due to vulnerabilities discovered over recent years. Consequently, SHA-2 has gained acceptance as a more secure alternative, offering stronger hash functions with support for larger hash sizes, making it suitable for modern applications. Using this combination of hashing algorithms allows network protocols to verify the integrity and authenticity of the transmitted packets effectively. In contrast, other options refer to encryption algorithms or methods that serve different purposes. AES and 3DES,