KarkomaOnline

MD5 is an algorithm developed by Ronald Rivest and is used to verify data integrity. It creates a 128 bit message digest from a file input that is unique, some kind of fingerprint for humans.

When you want to check the integrity of a file you have downloaded or you want to ensure the integrity of critical files on your system, MD5 will come in handy. The GNU coreutils package provides md5sum, a tool to compute and check MD5 message digest.

md5sum filename

And now that you know the checksum of filename, if any part of the file has been changed the md5 checksum will be different.

References:

• The MD5 Message-Digest Algorithm
• md5sum man pages

This entry was posted on Sunday, February 8th, 2004 at 5:50 pm and is filed under Security. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.