Network Defense Essentials (NDE) Practice Exam

The algorithm that uses a cryptographic key and a hash function to verify data integrity is HMAC (Hash-based Message Authentication Code). HMAC is specifically designed to combine a cryptographic hash function with a secret key for the purpose of ensuring the integrity and authenticity of a message.

In HMAC, a hash function processes both the data and the secret key in such a way that it produces a unique and fixed-size output (the HMAC). This output can be used to verify that the data has not been altered during transmission. If even a single bit of the data changes, the resulting HMAC will be different, indicating potential tampering.

The other algorithms listed serve different purposes: SHA-1 is a hashing algorithm that provides data integrity by generating a hash value, but it does not incorporate a cryptographic key. AES is a symmetric encryption algorithm used for data confidentiality, and RSA is an asymmetric encryption algorithm used for secure data transmission and digital signatures, but neither is designed specifically for data integrity using a key and hash function as HMAC is.