[loup-vaillant]

> monocypher does not seem to offer an asymmetric encryption primitive.

Neither do NaCl and Libsodium. Their `crypto_box()` is a construction that does key exchange, derives a key from the resulting key exchange, and finally use that key to perform symmetric authenticated encryption. I simply omitted that particular construction for Monocypher.

I've often asked be why. My reason is that the NaCl libraries (all 3 of them) are low-level, and a straightforward application of `crypto_box()` lacks the security properties we've now come to expect of modern key exchanges, most notably forward secrecy. To get up to that level would require implementing Noise, and I personally feel that's a tad out of scope. I reckon however that higher-level libraries that implement full protocols however are sorely needed.