basic authentication using apache tools

To create key value pair for username and password use following command at prompt

htpasswd -c

it will ask New Password:
and Re-type new password :

eg

htpasswd -c .htpasswd gayab

NOTE THAT

The MD5 algorithm used by htpasswd is specific to the Apache software. Passwords encrypted using it will not be usable with other Web servers.

Longer passwords will be truncated to 255 characters.

Usernames are limited to 255 bytes and may not include the character

Check out how you can configure apache server to handle basic authentication