Why it matters
Checksums can help confirm that a transfer or archived copy matches an expected file. The strength of the check depends on the algorithm and on whether the expected value comes from a trustworthy source.
A practical example
Imagine a laboratory records a file's cryptographic hash before transfer and compares it with the destination copy. A mismatch prompts investigation before the file is used in analysis.
An important distinction
A matching value does not prove that the original sample was correct or that the file was authorized. If someone can replace both the file and the expected checksum, the comparison may no longer provide the assurance intended.
Sources and further reading
- PRIMARY SOURCE NIST: Checksum
The example above is hypothetical. Related cases provide context; they do not imply that every case involved this mechanism.