Single sign-on buyer's guide
Why this guide matters
Choosing the right single sign-on solution is a critical decision because identity has become the new security perimeter. In a Zero Trust architecture, the firewall is less relevant; the Identity Provider (IdP) is the gatekeeper for all intellectual property and customer data. A fragmented or poorly negotiated SSO strategy can lead to vendor lock-in with exorbitant renewal costs. The right solution will improve security, reduce IT costs, and improve the employee experience.
What to look for
When evaluating SSO solutions, consider several key factors. Broad protocol support is essential to bridge legacy on-premise apps and modern SaaS applications. A large pre-built integration network can save significant implementation time and costs. High availability and failover capabilities are critical to ensure business continuity. Integration with multi-factor authentication (MFA) is a must-have for enhanced security. Finally, consider vendors that offer identity threat detection and response (ITDR) capabilities.
Evaluation checklist
- Critical SAML 2.0 & OIDC Support
- Critical MFA Enforcement
- Critical Directory Integration
- Critical High Availability SLAs
- Critical SOC 2 Type II / ISO 27001
- Important SCIM Provisioning
- Important Mobile App Support
- Important Self-Service Password Reset
- Nice-to-have Passwordless (FIDO2) Support
- Nice-to-have Access Certifications
Red flags to watch for
- Lack of Independent Security Audits
- Proprietary Protocols
- Opaque Pricing
- Weak Failover
- SSO Tax Enablers
From contract to go-live
Implementing SSO is a phased journey that typically spans 2 to 8 months for enterprise deployments. The discovery phase is critical for uncovering shadow IT and building a true app inventory. Identity cleanup is often the biggest bottleneck, requiring data cleansing and reconciliation. Configuration and testing involve setting up SAML connectors and conditional access policies. A phased rollout is essential to avoid overwhelming the help desk.
Implementation phases
Discovery & planning
2-4 weeksRequirements gathering, integration mapping
Identity Cleanup
2-4 weeksDuplicate users, inconsistent emails
Configuration
4-8 weeksSAML connectors, conditional access
Testing
2-4 weeksUAT, integration testing
Go-Live
1-2 weeksPhased Rollout, monitoring
Optimization
OngoingSCIM provisioning, advanced policies
The true cost of ownership
The base license fee is deceptive. The 'SSO Tax' charged by downstream apps and ancillary costs can double the Year 1 budget. Integrating legacy on-prem apps often requires specialized consulting. Usage-based overage fees can also add unexpected costs.
Compliance considerations for SSO
For global companies, GDPR requires understanding where the Identity Provider stores user data. The SSO system must integrate with the HRIS (Workday/BambooHR). If this link is broken, the automation of onboarding/offboarding fails, negating 50% of the value proposition. Evaluate whether the vendor has EU-specific data centers and can guarantee data sovereignty.
Your first 90 days
Success is measured not by deployment but by adoption and risk reduction. Users must be able to log in, and fallback accounts must be functional. Rapid resolution of login tickets is critical. By Month 1, aim for a 90% adoption rate. By Quarter 1, validate ROI by measuring password reset ticket reduction and onboarding time improvements.
Success milestones
- Admin access verified
- Fallback accounts functional
- Logins operational
- Login ticket resolution
- Business process verification
- Team training complete
- 90% adoption rate
- Decommission old logins
- User feedback collected
- ROI validation
- Phase 2 planning
- Vendor QBR scheduled
Measuring success
Measure success not just by operational metrics (uptime, tickets) but by security outcomes. Track the 'Time to Revoke' access for terminated users. Monitor the reduction in password reset tickets and onboarding time. Ensure SSO coverage extends to a high percentage of corporate apps.