Cisco Cyber Security Practice Exam

In cryptography, what is typically used to ensure data integrity?

1. Encryption

2. Hashing

3. Compression

4. Obfuscation

The correct answer is: Hashing

Hashing is primarily used to ensure data integrity in cryptography. When data is hashed, a fixed-size output known as a hash value or digest is produced from input data of any size. Even the slightest change in the original data—whether it's an added character or a modified byte—results in a significantly different hash value. This property is called the avalanche effect, and it makes hashes useful for verifying that data has not been altered. When data integrity is essential, such as in transmitting files over a network or storing sensitive information, a system can generate a hash value of the original data. Upon receipt or retrieval, the system computes the hash value of the data again and compares it with the original. If the two hash values match, it confirms that the data remains unchanged and intact. If they differ, it indicates that the data may have been tampered with or corrupted. While encryption also serves a purpose in securing data, its primary function is confidentiality, protecting against unauthorized access rather than ensuring that the data has not been modified. Compression reduces the size of data but does not provide any guarantees about its integrity. Obfuscation involves making data unclear or unintelligible, often to protect intellectual property or sensitive information, but it does not maintain data integrity