Simple file verification: Difference between revisions

Revision as of 16:21, 6 February 2005

Revision as of 21:56, 15 February 2005

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'''SFV''' is an [[abbreviation]] for ''simple file verification'', a [[checksum]] format using the [[CRC32]] algorithm to verify the integrity of files.

==Flaws==

[[CRC32]], and thus also SFV, is not an ideal format for [[Computer security|securely]] verifying data integrity, since the CRC32 format is vulnerable to intentional modification that cannot be detected. Other formats, such as [[SHA512]], are better suited for ensuring the authenticity of files.

[[MD5]] has also been used for this purpose, but it's now prone to the same attacks (after the discovery of an MD5 hash collision in August 2004, claimed to be found in only 1 hour on a low-grade computing cluster).

== Check sum ==

Files can become [[Data corruption|corrupted]] for a variety of reasons including: faulty [[Computer Storage|storage media]], errors in [[Transmission (telecommunications)|transmission]], write errors during [[copying]] or moving, and so on. SFV allows a person to ensure that a file has not become corrupted by comparing a [[Hash function|hash]] applied a file to see that they are equal. SFV also allows users to verify the authenticity of files, since if a file was changed (say, with the addition of malicious code) the hash 'fingerprint' of the file would change and alter the user that the authenticity of the file is in question.