Single Sign-On (SSO): The Key to Secure and Convenient Modern Authentication
Tags: sso, cybersecurity, infosec
Published: 2023-08-14 22:16:50

Single Sign-On(SSO) is an authentication system that allows users to use a single set of credentials to sign into multiple applications. This system is gaining popularity among many enterprises today due to its ease of use, which promotes a positive user experience and efficiency. 

Organizations are also learning to rely on it. As of 2022, as much as [87% of organizations](https://www.statista.com/statistics/1342529/global-deployment-level-single-sign-on-system-by-region/) in the EMEA region had implemented SSO, with others planning to do the same in the coming months. This allows them to safeguard their customers’ data while at the same time remaining compliant with the relevant authorities and maintaining their reputation. 

While there’s a promising trend in how many companies implement SSO, it is still a new technology to some. This article will dive into Single Sign-on technology and explore how it works, its benefits, and some considerations for organizations and security teams that might want to adopt its use. 
## How Does Single Sign-On(SSO) Work
Single Sign-On needs three components to work: 

1. A service provider – This is the applicant you want to access, e.g. a shopping website or social media site
2. Identity provider – a service or application that holds your identity information
3. User – You, who is trying to access the application

SSO establishes trust between the service provider and IdP by exchanging encrypted access tokens. The access token contains bits of information about you, such as your username and email address.
 
The idea is for the IdP to prove that you (the User) are who you claim to be (authenticate) to the service provider and gain access. This way, you don’t have to provide your credentials with every application you encounter personally. 
### SSO Workflow

![SSO Workflow- Don Esrom](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/24yfo53zfd5vriu1lrn7.png)
Single sign-on technology relies on a workflow between its components to maintain data security and a friendly user experience for anyone involved. Here is a detailed workflow of how SSO works. 

The journey starts with a User Access Request, where you, the user, try to access the Service Provider by clicking a link or navigating to its URL. 

Once done, the Service provider detects that you are not authenticated and redirects you to the IdP. The IdP then prompts you to enter your credentials ( (username and password) and authenticates you if your credentials are credible. 

Once authentication happens, the IdP generates an SSO token (security assertion) for the user and sends the SSO token to your browser through a redirect to the Service Provider.

Finally, the Service Provider receives the SSO token, verifies its authenticity with the IdP, and grants you access.
## Supported Protocols for SSO
The process goes through some SSO-specific protocols and frameworks for this workflow to succeed and for authentication to occur. Protocols are special rules and languages that computers and websites use to communicate securely. 

 Below are 3 of the most popular protocols and frameworks for SSO. 

- SAML (Security Assertion Markup Language) – This is used to exchange information between your computer and the web. It is like a contract between your computer and the websites you want to interact with. 
- OAuth – This framework allows you to grant third-party applications access to your protected resources without sharing your passwords. This happens by exchanging tokens between the user, the resource owner, and the third-party application. 
- OpenID Connect (OIDC) – This is a secure mechanism that provides third-party applications with user details from an identity provider in a secure way. It is built on top of OAuth 2.0 to provide SSO functionality.
 
## Benefits of SSO
SSO is a valuable solution for many organizations of all sizes. Some benefits you can expect from using SSO as an authentication service include.
### Enhanced User Experience 
SSO improves user experience by eliminating the need to remember multiple usernames and passwords for all our online activities. 

This allows users to seamlessly move from one service to another without the hassle of repeatedly logging in. 
### Improved Security
SSO is considered a more secure form of authentication for several reasons. For example, users only have to remember one strong password. Also, different SSO systems have robust security measures to protect your personal information. 
### Reduced IT costs
Setting up and managing passwords and provisioning access to applications is sometimes costly. SSO makes it easier for organizations to simplify the authentication process without compromising the security of their data. 

Also, using SSO frees up the work the IT staff has to handle, allowing them to focus on other areas of development. 
### Improved Scalability 
SSO can be scaled as the organization grows. This allows organizations to avoid setting up new authentication solutions every time they experience growth.
## Types of SSO Implementations
SSO comes in different types and flavors to fit different needs. While each of these flavors does essentially the same thing, they are all designed differently depending on an organization’s needs. Here are a few popular implementations. 
### Enterprise SSO
This type of implementation caters to organizations with an extensive IT infrastructure. With an enterprise SSO, the service provider uses a single IdP to authenticate users and provide access to all applications and websites within the organization.
 
Examples of organizations that use this implementation include Google, Microsoft, Amazon, and IBM. 
### Web-Based SSO
This SSO implementation helps improve and simplify user experience when accessing multiple websites. With web-based SSO, a single IdP authenticates users and allows them to access different websites without repeatedly producing their credentials. 

A good example of a web-based SSO is the “Sign in with Google” option that you get when trying to access different websites. 
### Federated SSO
Federated SSO implementation allows users to authenticate with one IdP and access applications and websites hosted by different organizations. It is a valuable security option for organizations that need to collaborate with partners and customers. 

Also, organizations with complex IT infrastructure and multiple applications and websites can benefit from this implementation. 
## SSO Challenges and Considerations
SSO comes with numerous benefits that fit into many organizations’ security interests. Its ease of use across the board fits most organizations' need to provide a seamless yet safe experience for many internal and external users. 

However, SSO also faces challenges that organizations and security teams should consider before using it. Looking into these potential roadblocks will make it easier for security and IT teams to prepare and find mitigation strategies. 
### Security and Privacy Concerns
SSO is a great option that provides users with a single secure gateway to access multiple resources and services. However, if SSO credentials leak, the same gateway will be accessible to threat actors. 

It is, therefore, always important to secure all SSO implementations that an organization or business chooses to adopt. A great way to do this is to couple it with other security controls, such as Multifactor Authentication (MFA), to protect against unauthorized access. 
### Implementation Complexity
Setting up a Single Sign-on implementation and system can be complex and time-consuming. Security teams must integrate their systems with IdPs, configure trust relationships, and secure compatibility with various applications. 

Organizations can navigate this by employing the right experts and carefully planning any implementation to prevent disruption and vulnerabilities in the system. 
### User Consent and Control
While SSO is a convenient option for users, it often involves granting permission for applications to access their data. This raises questions about how much control users have over their data. 

Therefore, organizations must provide clear visibility into which services are accessing user data and the ability to revoke access when needed. 
### Vendor Lock-In
There are different SSO solutions from different vendors. When an organization adopts a specific SSO solution, it might tie them to one particular vendor. This can limit flexibility and cause challenges if the organization wants to switch or expand its technology stack in the future. 

Therefore, security teams should always consider the long-term implications of vendor choice.
## Real-World Examples of SSO
Here are a few real-world examples of companies and platforms that utilize Single Sign-On (SSO) solutions to simplify user access.
### Google
Google offers a widely recognized SSO solution. You can access various Google services such as Gmail, Google Drive, Google Docs, YouTube, and more if you have a Google account. 

Once logged in to one Google service, you're automatically signed in to others without re-entering your credentials.
### Microsoft Azure AD
Microsoft's Azure Active Directory (Azure AD) provides SSO capabilities for a range of Microsoft services, including Microsoft 365 (Office 365), Microsoft Teams, and SharePoint. Users can log in once and access multiple Microsoft applications seamlessly.
### Facebook Login
Many websites and apps offer "Login with Facebook" as an SSO option. You can use your Facebook credentials to quickly sign in to various third-party websites and apps without creating new accounts or remembering additional passwords.
### Salesforce
Salesforce, a customer relationship management (CRM) platform, offers SSO integration for its suite of applications. Users can log in to the Salesforce ecosystem with a single set of credentials and access various services, such as Sales Cloud, Service Cloud, and Marketing Cloud.
### Amazon Web Services (AWS)
AWS provides SSO capabilities for its cloud services. Users within an organization can log in to the AWS Management Console using their company credentials and access various cloud resources without separate logins for each service.
### Apple Sign-In
Apple's "Sign in with Apple" feature is an SSO solution that enhances privacy. Users can use their Apple ID to sign in to apps and websites, avoiding the need to create new accounts. Apple offers options to share or hide personal information when signing in.
## Conclusion
SSO has emerged as a beacon of efficiency and security, making it easier for people and organizations to conduct business online more securely. 

This authentication technology allows users to enjoy seamless access to their favorite apps and organizations to meet some requirements to safeguard sensitive data. This has happened through federated, web-based, and enterprise implementations. 

As technology advances, we expect SSO to improve in elevating the user experience further while ensuring the utmost security of our precious data.