Top 20 NuGet Security Packages

Roslyn analyzers that aim to help security audits on .NET applications.
AspNetCore.Security.CAS Class Library
Secure Token Service, IdentityBase web interface
.NET Standard 1.3 implementation of the Noise Protocol Framework (revision 33 of the spec)
The TeleSign C# SDK lets you easily integrate with our REST API.
This package contains the runtime assemblies for ASP.NET Web Pages. ASP.NET Web Pages and the new Razor syntax provide a fast, terse, clean and lightweight way to combine server code with HTML to create dynamic web content.
Microsoft.Owin 3.1 Authentication Middleware for JBoss Keycloak 3.2
ASP.NET Core security middleware enabling Yahoo authentication.
ASP.NET Core security middleware enabling Vkontakte authentication.
ASP.NET Core security middleware enabling StackExchange authentication.
ASP.NET Core security middleware enabling Slack authentication.
ASP.NET Core security middleware enabling Autodesk authentication.
ASP.NET Core security middleware enabling Discord authentication.
SRP-6a protocol implementation for .NET Standard 2.0 and .NET Framework 3.5+
Official Okta middleware for ASP.NET 4.5+. Easily add authentication and authorization to ASP.NET applications.
OWIN middleware for providing a resource/action based authorization manager.
Effortless .Net Encryption is a library that provides: Rijndael encryption/decyption, Hashing and Digest creation/validation and Password/salt creation.
A compatibility layer for sharing authentication tickets between Microsoft.Owin.Security and Microsoft.AspNetCore.Authentication.
A powerful .Net component for managing permission entries in content repositories.
Entity Framework data provider implementation for the SenseNet.Security project.