Hi,
For security I would advise to do the following. Create the following files in your admin directory with the content:
1 .htaccess
Code:
RewriteEngine Off
AuthType Basic
AuthName "Administration Area"
AuthUserFile /full_path_to_your_subrion_directory/admin/.htpasswd
Require valid-user
2 .htpasswd
.htpasswd Content Generator
You can use the tool above to generate username and password. Simply copy the generated line in your .htpasswd file and that's all.
In this case you will have double defence
Let me know if you have any questions.