SAP Secure Login Service for SAP GUI:
The Successor to SAP Single Sign-On 3.0

SAP Single Sign-On 3.0 (SSO) will reach end of maintenance at the end of 2027 and is being replaced by the cloud-based SAP Secure Login Service (SLS). Organizations are therefore facing the need to modernize their authentication landscape end to end and align it with Zero Trust security principles consistently across all access channels.

The path to modern, Zero Trust-ready SAP authentication

Studies show that over 80 percent of all security incidents are caused by stolen or weak credentials. In 2024 alone, more than five billion user accounts were compromised worldwide. This is a clear signal that traditional password-based authentication models are no longer sufficient.

In SAP environments, password-related issues also have a measurable business impact. Resetting forgotten SAP passwords causes an average productivity loss of more than 11 hours per employee per year. As a result, modern Single Sign-On and Multi-Factor Authentication mechanisms are no longer optional. They are a core requirement of any serious Zero Trust strategy.

For more than a decade, SAP Single Sign-On 3.0 has been the established standard for passwordless authentication in SAP systems. Millions of users authenticate every day using Kerberos or X.509 certificates. The solution is stable, proven, and widely trusted. However, time is running out.

On December 31, 2027, SAP will end maintenance for SAP SSO 3.0, including the SAP NetWeaver AS Java platform that hosts critical components such as the Secure Login Server. At the same time, cloud-first strategies, Zero Trust architectures, and regulatory requirements such as NIS2, ISO 27001, GDPR, and internal security audits are fundamentally changing expectations around authentication.

Today, organizations must do more than just enable Single Sign-On. They must enforce Multi-Factor Authentication, device trust, conditional access, and centralized security policies across all access channels, including SAP GUI, SAP Fiori, SAP BTP, SaaS applications, and partner access.
This shift makes it clear that classic on-premises authentication approaches are no longer sufficient. A strategic transition is required.

While web, cloud, and SaaS applications can already be integrated easily with modern identity providers, SAP GUI remains a special case. The proprietary SNC protocol does not support SAML or OpenID Connect and relies exclusively on Kerberos or X.509. As a result, SAP GUI does not naturally fit into Zero Trust or conditional access models. This is exactly the gap that SAP Secure Login Service closes.

Why migrating to SAP Secure Login Service (SLS) is a strategic necessity

SAP Secure Login Service is SAP’s recommended successor to SAP Single Sign-On 3.0. The move to SLS is not only technically required but also essential from a security and Zero Trust perspective.

Many organizations find themselves in a situation where their existing SSO setup still works technically, but is approaching its strategic end of life:

Note: Kerberos remains a reliable and proven technology, but it is tightly coupled to Active Directory environments and lacks native support for modern Zero Trust controls. Modern security requirements such as device-based trust, conditional policies, or dynamic MFA decisions cannot be implemented with Kerberos alone. This is where traditional on-premises authentication reaches its technical limits.

SAP Secure Login Service provides the answer for SAP GUI authentication. As part of the SAP Cloud Identity Services portfolio, SLS replaces long-lived Kerberos tickets with short-lived, non-exportable X.509 certificates issued by the SAP Trust Center. Authentication is controlled by the corporate identity provider, such as Microsoft Entra ID, Okta, or Ping Identity.

How SAP Secure Login Service (SLS) works

SAP Secure Login Service connects SAP GUI with modern cloud identity standards. Certificates are issued dynamically, policies are enforced centrally, and passwords are fully eliminated.

The authentication flow is streamlined and robust:

  1. The user starts SAP GUI
  2. The Secure Login Client authenticates the user via SAP Identity Authentication Service (IAS) against the corporate identity provider
  3. Security policies, MFA, and device compliance checks are enforced
  4.  SAP Secure Login Service issues a short-lived, non-exportable X.509 certificate
  5. SAP GUI uses this certificate via SNC and CommonCryptoLib to securely log on to the ABAP system

The modern Secure Login Client includes an integrated, hardened browser for the first time. This allows SAP GUI to use the same SAML or OIDC-based login flows as modern cloud applications, including MFA, conditional access, and device compliance.

Process of SAP Secure Login Service authentication with SAP GUI, Identity Authentication Service, the corporate identity provider, and the issuance of an X.509 certificate by the SAP Cloud CA.
Figure 1: Authentication flow with SAP Secure Login Service

Typical migration paths in real-world projects

The transition from SAP SSO 3.0 or pure Kerberos environments to SAP Secure Login Service is not a simple plug-and-play activity. It is a structured modernization project with clearly defined phases.

1.  Analysis and target architecture

  • Assessment of the current authentication landscape, including Kerberos, X.509, SAML, and OIDC
  • Definition of a hybrid authentication strategy aligned with Zero Trust and external access requirements
  • Evaluation of IAS tenant strategy and naming conventions
  • Assessment of impacts on existing roles and authorization concepts

2. Architecture and design

  • Establishment of trust relationships between Entra ID, IAS, and SAP systems
  • Definition of the claim mapping strategy using UPN, email, or UUID
  • Integration of Identity Provisioning Service and SCIM for persistent identities in the Identity Directory
  • Design of a standardized authentication model across all access channels
 
3. Proof of Concept
 
  • Technical validation using real end-user devices
  • Coexistence of Kerberos and SLS
  • Validation of HTTP and ICF services, including SPNEGO and SAML fallback
  • Review of user experience and operational impact
 
4. Pilot and rollout
 
  • Deployment of the Secure Login Client to pilot user groups
  • Internal communication and awareness activities
  • Phased rollout by system landscape or region
  • Monitoring and stabilization of the target environment
 
5. Decommissioning und Governance
 
  • Shutdown of the legacy Secure Login Server
  • Consolidation of authentication on IAS and Entra ID
  • Monitoring, recertification, device compliance, and SIEM integration
  • Establishment of long-term operating models and responsibilities

Best practices and lessons learned from projects

A key success factor in Secure Login Service projects is a planned coexistence phase. Running SAP SSO 3.0 and SAP Secure Login Service in parallel allows organizations to maintain stability while validating different usage scenarios under real-world conditions.

Persistent user identities in the Identity Directory Service are equally important. Only users with a stable UUID can fully leverage modern SAP cloud services. Experience also shows that a consistent claim design, including clear naming conventions, is critical to avoiding login errors.

Projects repeatedly highlight the importance of addressing the following topics early:

Zero Trust goes far beyond MFA. It requires continuous evaluation of context, device trust, and access conditions. User acceptance ultimately depends on clear communication around why these changes are necessary and how they improve security.

Architecture overview

The Secure Login Service architecture is based on a clear separation of responsibilities between identity source, policy enforcement, and certificate issuance. This results in a unified, cloud-ready authentication model without local servers.

At the core of the architecture are the SAP Cloud Identity Services. SAP Identity Authentication Service (IAS) acts as the central authentication broker and policy enforcer. The Identity Directory Service (IdDS) provides persistent user identities, including UUID or Global User ID. SAP Identity Provisioning Service (IPS) with SCIM manages provisioning and identity lifecycle processes across connected systems.

SAP Secure Login Service issues short-lived, non-exportable certificates for SAP GUI, while the Secure Login Client on end-user devices ensures secure access. In many environments, Microsoft Entra ID acts as the primary corporate identity provider, although other IDPs can be used as well.

This architecture enables consistent authentication across all access channels, centralized MFA and policy enforcement, and unified logging in a fully cloud-based operating model. No local servers and no Java stack are required.

Licensing and cost model

SAP Secure Login Service is licensed via SAP Business Technology Platform using a subscription model. The pricing structure is transparent and includes the required identity services, significantly reducing operational effort.

Key facts include:

  • Subscription via SAP Business Technology Platform
  • Billing in blocks of 500 users, approximately EUR 5,400 per year
  • Two SCI-Tenants (IAS, IPS, and IdDS) included
  • No local servers and no additional maintenance effort
  • Licensing handled through the SAP Account Executive

The real economic benefit comes from reduced password resets, fewer help desk tickets, and lower audit effort. Many organizations see measurable savings shortly after go-live.

Xiting as your partner for SAP Secure Login Service

Implementing SAP Secure Login Service is a strategic modernization initiative that requires deep technical expertise and a solid understanding of Zero Trust architectures. Xiting supports organizations throughout the entire journey, from initial assessment to stable operations.

The move from SAP SSO 3.0 or Kerberos to Secure Login Service impacts identity architecture, governance, processes, and security policies. Xiting supports this transition with a structured approach and extensive project experience.

Our services include:

  • Workshops and assessments to analyze the current authentication landscape
  • Proof of Concept and pilot implementations, including coexistence scenarios
  • Rollout support and hypercare
  • Training and enablement of internal teams

We provide independent consulting without license-driven incentives. Our experience from numerous SSO and SLS projects forms the foundation for secure, sustainable, and future-proof IAM architectures, with a strong focus on governance and operational security.

“When we started rolling out Kerberos and SNC in 2010, it was a major milestone. But authentication requirements have changed significantly. Today, we need flexible, context-aware signals, MFA, and device trust. That is why SAP Secure Login Service is the necessary next step.”
Carsten Olt
IAM-Expert at Xiting

Conclusion

Migrating to SAP Secure Login Service is unavoidable, but it is far more than a mandatory task. It is an opportunity to modernize SAP authentication, embed Zero Trust principles, and bridge the gap between traditional on-premises systems and modern cloud identity platforms.

Key benefits of SAP Secure Login Service include:

  • Unified authentication across SAP GUI, Fiori, and SAP BTP
  • MFA and conditional access for SAP GUI
  • No Java stacks and no local SSO infrastructure
  • Strong audit capabilities with centralized logging and SIEM integration
  • Reduced password risk and lower support costs

Learn more in our Security Wednesday series:

Start with a discovery workshop

We analyze your current SSO landscape, define the target architecture, and create a migration roadmap

Carsten Olt

Head of Identity & Access Management

Weitere Informationen können Sie unter anderem in unserer Security Wednesday Reihe erfahren:

FAQ

What is SAP Secure Login Service (SLS)?

SAP Secure Login Service is the cloud-based successor to SAP Single Sign-On 3.0. It provides short-lived, non-exportable X.509 certificates for SAP GUI and supports MFA, conditional access, and device trust.

Maintenance for SAP SSO 3.0 and the underlying NetWeaver AS Java platform ends on December 31, 2027. This removes the technical foundation for the Secure Login Server.

Kerberos is not Zero Trust capable and does not support real-time MFA or context evaluation. SLS uses centrally controlled, short-lived certificates and integrates with cloud identity platforms.

SLS enables secure SAP GUI authentication with MFA, device-based security, and centralized policies – without requiring local Secure Login Server infrastructure.

Yes. A planned coexistence phase is common and helps reduce migration risk. Kerberos and SLS can operate in parallel using the Secure Login Client.

Licensing is handled via SAP BTP in blocks of 500 users and includes IAS, IPS, and IdDS.

IAS acts as the central authentication broker between the corporate identity provider and SAP systems and enforces security policies.

An IAS tenant, integration with a corporate identity provider, and deployment of the Secure Login Client are required. Persistent identities in the Identity Directory Service improve interoperability with SAP cloud services.

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