Apache Reference: mod_digest
mod_digest - User Authentication by User Name/Realm/Password
Since Apache 1.1,
src/modules/standard/mod_digest.c
Rob McCool, Robert S. Thau, Alexei Kosut (1996)
In addition to the classical HTTP/1.0 Basic
Authentication mechanism, a message digest-based HTTP
authentication mechanism exists as defined in RFC
2617.()ftp://ftp.isi.edu/in-notes/rfc2617.txt> Instead of
transferring a clear-text user name/pass==word pair with the
HTTP request (which can be easily monitored), a message digest
is calculated (via the MD5 algorithm) and transferred together
with the user name. This module then performs the same message
digest calculation for the password stored in the server's
authentication database. When the two digests are equal, access
is allowed. This approach offers an obvious advantage relative
to Basic Authentication: the password is not sent over the
network. The drawback is that many browsers do not support this
type of user authentication.
Directive: