Full Discussion (PHP 7.2: The First Programming Language to Add Modern Cryptography to its Standard Library)

How about C#? That hasn't got modern cryptography built-in?

No, it doesn't.

Please, everyone, look at the documentation for the language you're writing in and compare it to the established criteria of this post before you ask about it.

C# gives you NIST curves, not modern ECC (RFC 7748). C# doesn't give you a simple misuse-resistant AEAD interface like crypto_secretbox() or crypto_box() as part of the standard API. Therefore, it's not modern cryptography.

Weierstrass curves are not modern.

You can get that if you install libsodium-net by Adam Caudill. But that's not part of the language, that's a community-provided addon.

code of conduct - report abuse