(@url{https://tools.ietf.org/html/rfc7091.html, RFC 7091})
public key signature function
@item various 34.10 curve parameters included
+@item Coordinates conversion from twisted Edwards to Weierstrass
+ form and vice versa
@item VKO GOST R 34.10-2001 key agreement function
(@url{https://tools.ietf.org/html/rfc4357.html, RFC 4357})
@item VKO GOST R 34.10-2012 key agreement function