What does a checksum help to verify?

A checksum is a calculated value used to verify the integrity of data during storage or transmission. When data is sent over a network or written to a storage medium, a checksum is generated based on the content of that data. Upon receiving or retrieving the data, the system can re-calculate the checksum and compare it with the original. If the checksums match, it indicates that the data has not been altered or corrupted during the process, thus confirming its integrity.

This mechanism is critical in detecting errors that may occur due to various reasons such as hardware malfunctions, software bugs, or transmission issues. By focusing on data integrity, checksums ensure that the information remains accurate and reliable, which is essential for maintaining the trustworthiness of data in various applications, especially in cybersecurity, where the authenticity of data can significantly impact the overall security posture.

The other options do not relate to what a checksum is designed to achieve. Data storage capacity refers to how much data can be held by a device, data transfer speed pertains to the rate at which data can be transmitted, and data accessibility deals with how easily data can be reached or used by authorized parties. None of these relate to verifying if the data remains unchanged, which is the primary function of a checksum.