Explore authentication and authorization in Blazor with this comprehensive NDC London 2021 conference talk. Dive deep into the security model of Blazor, understanding the components involved and the differences between Blazor Server and Web Assembly. Learn how to integrate Blazor applications with Identity Server 4 and use OAuth for secure API calls. Discover the implementation of roles and policies to achieve greater abstraction over user permissions and actions. Examine the changes needed to support offline mode in Progressive Web Applications (PWAs). Cover topics such as the Object Model, Authorization Root View, Authentication State Provider, Blazor Server Providers, Blazor Web Assembly, Access Tokens, Roles implementation, Claims Principle Factory, Identity Server integration, Weather API, Permissions middleware, and custom array claims. Gain practical insights through demonstrations and examples to enhance your Blazor application's security architecture.