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

==Check sum==

Files can become 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 alert the user that the authenticity of the file is in question.

One of the first programs to use the SFV format was WinSFV.

SFV uses a plain-text file containing one line for each file and its checksum in the format FILENAME CHECKSUM. Any line starting with a semicolon ; is considered to be a comment line and is ignored for the purposes of file verification. A sample SFV file appears as follows:

file1.zip c45ad668 file2.zip 7903b8e6 file3.zip e99a65fb

=Flaws=

The hash function used by SFV, CRC32, is not a cryptographically secure hash function. It is easy to intentionally create a file with a given CRC32 checksum. The fact that a file s checksum corresponds with the checksum in the SFV file is therefore no guarentee that the file has not been tampered with. However, SFV is well suited to detect random changes.

Other hash functions, such as SHA512, are better suited for ensuring the authenticity of files. But this is only helpful if there is a secure second channel to get the checksums.

=See also=

= External links =