The Side Project by Maarten Balliauw

Duende Software is a company that builds industry-leading security software.

This isn't a point release. This is a new chapter. On June 2, Duende ships the most significant release in the company's history: IdentityServer v8 - a .NET 10-exclusive major release, five modular…

Learn more about the Next Era of Duende Identity Infrastructure including IdentityServer v8, modular add-ons, a new infrastructure foundation, and more.

Learn more about the Next Era of Duende Identity Infrastructure including IdentityServer v8, modular add-ons, a new infrastructure foundation, and more.

Learn more about the Next Era of Duende Identity Infrastructure including IdentityServer v8, modular add-ons, a new infrastructure foundation, and more.

Learn more about the Next Era of Duende Identity Infrastructure including IdentityServer v8, modular add-ons, a new infrastructure foundation, and more.

Future-proof your apps with Duende's identity modernization. Get better security and control while preserving your existing identity logic.

An overview of modern application architecture patterns and how OpenID Connect and OAuth 2.0 protocols implemented by IdentityServer solve authentication and API access challenges

Guidance on the high-severity CVE-2026-40372 vulnerability in Microsoft.AspNetCore.DataProtection. Learn how attackers can use it, check if your application is affected, and find the critical steps…

The most flexible and standards-compliant OpenID Connect and OAuth framework for ASP.NET Core.

SAML isn't legacy — it's entrenched. Tracing the protocol from its 2001 origins through its enduring role in enterprise, government, and academic identity federation, and what it means for…

Stop bloating your authentication cookies. Use Duende IdentityServer server-side sessions and AuthenticationProperties to store dynamic user metadata (like location) on the server, which improves…

Stop writing boilerplate code for ClaimsPrincipal. C# 14 extension members let you use properties to centralize claim access logic, leading to cleaner, more secure ASP.NET Core applications.

Join us March 24 for a first look at Duende User Management. Learn to replace ASP.NET Identity with built-in Passkeys, MFA, and audits.

Future-proof your apps with Duende's identity modernization. Get better security and control while preserving your existing identity logic.

Learn about the Client-Initiated Backchannel Authentication (CIBA) standard, an OpenID Connect extension for authenticating users on a separate device. See how to implement this high-trust flow with…

Are your APIs vulnerable? Explore JWT pitfalls, learn to prevent exploits, and compare JWTs vs. opaque tokens in this expert-led session.

Learn why rate limiting Duende IdentityServer endpoints is usually unnecessary, and when you do need it. Explore a layered approach using network proxies, ASP.NET Core middleware, and custom…

An overview of modern application architecture patterns and how OpenID Connect and OAuth 2.0 protocols implemented by IdentityServer solve authentication and API access challenges

Learn how to enforce strict trust boundaries between your APIs and prevent overprivileged access tokens by adopting Resource Isolation, based on OAuth 2.0's RFC 8707, with Duende IdentityServer.

In this video, we look deeper into critical security-related HTTP headers that can significantly strengthen your website's defenses. What you'll learn in this video: * X-Content-Type-Options:…

The most flexible and standards-compliant OpenID Connect and OAuth framework for ASP.NET Core.

Duende Software's latest Open Source Sponsorship goes to BenchmarkDotNet, a benchmarking library for .NET.

YouTube video by NDC Conferences

Learn the core benefits of building a federation gateway that brings together Entra ID, Okta, SAML, Auth0 though a centralized authentication provider like DUende IdentityServer.

🏷 Minimalistic versioning using Git tags. Contribute to adamralph/minver development by creating an account on GitHub.

Learn the core benefits of building a federation gateway that brings together Entra ID, Okta, SAML, Auth0 though a centralized authentication provider like DUende IdentityServer.

Check out the Duende Insiders community on Discord – hang out with 42 other members and enjoy free voice and text chat.

We invite you to join a deeply technical, standards-driven community to help shape the future of .NET security and identity.

Secure frontend apps with the Backend for Frontend (BFF) pattern. Simplify token management and boost security using Duende BFF v4, with multi-frontend support.

Check out the Duende Insiders community on Discord – hang out with 42 other members and enjoy free voice and text chat.

Check out the Duende Insiders community on Discord – hang out with 42 other members and enjoy free voice and text chat.

Duende BFFv4 is now available! Learn about multi-frontend, simplified security, and unlock end-to-end visibility with OpenTelemetry.

Check out the Duende Insiders community on Discord – hang out with 42 other members and enjoy free voice and text chat.

Learn the core benefits of building a federation gateway that brings together Entra ID, Okta, SAML, Auth0 though a centralized authentication provider like DUende IdentityServer.

Duende BFFv4 is now available! Learn about multi-frontend, simplified security, and unlock end-to-end visibility with OpenTelemetry.

How to use the Microsoft.SBOM.Targets NuGet package to produce a Software Bill of Materials (SBOM) during your release builds.

Ever wondered how browsers determine what kind of content they're displaying? It's usually through the Content-Type header. But what happens when that's missing or incorrect? That's where MIME type…

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