→Patching: remove uncited, and worse, completely redundant "yes, you need to check signatures" information; there's literally no point in saying the same thing for dpkg, apt and source archives.
Operating systems, like all software, may contain bugs in need of fixing or may be enhanced with the addition of new features. Patching the operating system in a secure manner requires that the software come from a trustworthy source and not have been altered since it was packaged. Common methods for verifying that operating system patches have not been altered include the use of the [[digital signature]] of a [[cryptographic hash]], such as a [[SHA-2|SHA-256]] based checksum, or the use of read-only media.{{Citation needed|date=April 2024}}
From a security standpoint, the specific packaging method, such as the [[Dpkg|dpkg package manager]] or the [[RPM Package Manager]] format originally from [[Debian]] and [[Red Hat Linux]], respectively is not as important as the use of features which ensure the integrity of the patch itself.
====Source distributions====
Source distributions include the ability to examine the code for suspicious content. The drawback, absent an accompanying cryptographic hash value, is that the user must be able to perform a security analysis of the code themselves.
====RPM packages====
[[Linux]] distributions which use the [[RPM Package Manager]] format for providing base functionality and software updates make use of [[MD5|cryptographic hash]]<nowiki/>es and [[GNU Privacy Guard|GPG]] to ensure content integrity. The hash values are packaged with the RPM file and verified when the package is installed.
====Debian packages====
[[Linux]] distributions which use the [[Debian]] [[Deb (file format)|.deb package format]] for providing base functionality and software updates make use of [[GNU Privacy Guard|GPG]] signatures to ensure content integrity. A signature is computed when the package is constructed and verified later when the package is installed.
====Other vendors and distributions====
Regardless of the vendor or distribution, all software distributions should provide a mechanism for verifying that the software is legitimate and has not been modified since it was originally packaged.
