What is the primary role of hashing in data integrity?

Hashing plays a critical role in ensuring data integrity by providing a method to validate the consistency of messages. When data is hashed, it is converted into a fixed-size string of characters, which represents the original data in a unique way. Any slight change in the original data will result in a significantly different hash value. This property makes hashing an efficient way to check if the data has been altered or corrupted during transmission or storage.

For example, when a message is sent over a network, both the sender and the receiver can compute the hash of the original message. The receiver can then compute the hash of the received message and compare it with the hash sent by the sender. If both hashes match, it confirms that the message has not been altered, thereby validating its integrity.

The other options listed do not relate directly to the primary purpose of hashing in the context of data integrity. Efficient data retrieval pertains more to indexing and database management, encryption focuses on securing data from unauthorized access, and file compression is aimed at reducing storage space rather than ensuring consistency. Thus, the most appropriate choice reflecting the role of hashing in data integrity is the validation of message consistency.