Microsoft account or MSA(previously known as Microsoft Passport .NET Passport, Microsoft Passport Network, and Windows Live ID) is a single sign-on web service developed and provided by Microsoft that allows users to log in to websites (like Outlook.com), devices (e.g. Windows 10 computers and tablets, Windows Phones, or Xbox consoles), and applications (including Visual Studio) using one account.
Microsoft account allows users to sign in to websites that support this service using a single set of credentials. Users’ credentials are not checked by Microsoft account-enabled websites, but by a Microsoft account authentication server. A new user signing in to a Microsoft account-enabled website is first redirected to the nearest authentication server, which asks for username and password over an SSL connection. The user may select to have their computer remember their login: a newly signed-in user has an encrypted time-limited cookie stored on their computer and receives a triple DES encrypted ID-tag that previously has been agreed upon between the authentication server and the Microsoft account-enabled website. This ID-tag is then sent to the website, upon which the website plants another encrypted HTTP cookie in the user’s computer, also time-limited. As long as these cookies are valid, the user is not required to supply a username and password. If the user actively logs out of their Microsoft account, these cookies will be removed.
Microsoft account offers a user two different methods for creating an account:
- Use an existing e-mail address: Users are able to use their own valid e-mail address to sign up for a Microsoft account. The service turns the requesting user’s e-mail address into a Microsoft account. Users may also choose a password of their own choice.
- Sign up for a Microsoft e-mail address: Users can also sign up for an e-mail account with Microsoft’s webmail services designated domains (i.e. @hotmail.com, @live.com, @msn.com, @passport.com and @outlook.com or any variant for a specific country) that can be used as a Microsoft account to sign in to other Microsoft account-enabled websites.
Microsoft websites, services, and apps such as Bing, MSN and Xbox Live use Microsoft account as a mean of identifying users. There are also several other companies that use it, such as the Hoyts website which is hosted by NineMSN.
Windows XP and later has an option to link a Windows user account with a Microsoft account, thus automatically logging users in to their Microsoft account whenever a service is accessed. Starting with Windows Server 2012, Windows allows users to directly authenticate into their PCs using their Microsoft account rather than a local or domain user.