The Authentication Package 
The authentication package provides a simple interface to authenticate users in a Joomla Framework application. It is completely decoupled from the application class and provides the ability to implement custom authentication strategies.
Installation via Composer
Add "joomla/authentication": "~1.0" to the require block in your composer.json and then run composer install.
{
"require": {
"joomla/authentication": "~1.0"
}
}Alternatively, you can simply run the following from the command line:
composer require joomla/authentication "~1.0"If you want to include the test sources and docs, use
composer require --prefer-source joomla/authentication "~1.0"