Checking Package Integrity

The md5sum command is used to compute a 128-bit fingerprint that is strongly
dependant upon the contents of the file to which it is applied. It can be used to
compare against a previously-generated sum to determine whether the file has
changed. It is commonly used to ensure the integrity of updated packages
distributed by a vendor:
# md5sum package-name
995d4f40cda13eacd2beaf35c1c4d5c2 package-name
The string of numbers can then be compared against the MD5 checksum
published by the packager. While it does not take into account the possibility that
the same person that may have modified a package also may have modified the
published checksum, it is especially useful for establishing a great deal of
assurance in the integrity of a package before installing it.