title: System.Security.Cryptography not found
body: <p>I am trying to add a reference to System.Security.Cryptography.X509Certificates but I get: "The type or namespace 'Cryptography' does not exist in the namespace 'System.Security'.</p>
  
  <p>I have tried adding System.Security to references, I have tried adding System.Security.dll, I have tried adding mscorlib.dll, I have tried to find how to add Windows.Security.Cryptography.</p>
  
  <p>No luck, therefore I cannot use the X509Certificate2 class, which I need.</p>
  
  <p>Has anyone run into this impossibly frustrating situation?</p>
  
  <p>UPDATE:</p>
  
  <p>Looking at this question, <a href="https://stackoverflow.com/questions/34345271/randomnumbergenerator-in-asp-net5">RandomNumberGenerator in ASP.NET5</a>
  I cannot find what I am looking for in Nuget. In nuget, I only see System.Security.Cryptography.Hashing.Algorithms.Analyzers. I need System.Security.Cryptography.X509Certificates</p>